Showing papers in "American Journal of Medical Genetics Part A in 2012"

Microtia: Epidemiology and genetics

Abstract: Microtia is a congenital anomaly of the ear that ranges in severity from mild structural abnormalities to complete absence of the ear, and can occur as an isolated birth defect or as part of a spectrum of anomalies or a syndrome. Microtia is often associated with hearing loss and patients typically require treatment for hearing impairment and surgical ear reconstruction. The reported prevalence varies among regions, from 0.83 to 17.4 per 10,000 births and the prevalence is considered to be higher in Hispanics, Asians, Native Americans, and Andeans. The etiology of microtia and the cause of this wide variability in prevalence are poorly understood. Strong evidence supports the role of environmental and genetic causes for microtia. Although some studies have identified candidate genetic variants for microtia, no causal genetic mutation has been confirmed. The application of novel strategies in developmental biology and genetics has facilitated elucidation of mechanisms controlling craniofacial development. In this paper we review current knowledge of the epidemiology and genetics of microtia, including potential candidate genes supported by evidence from human syndromes and animal models. We also discuss the possible etiopathogenesis in light of the hypotheses formulated to date: neural crest cells disturbance, vascular disruption and altitude.

Teratogenicity of mycophenolate confirmed in a prospective study of the European Network of Teratology Information Services.

Abstract: After maternal exposure to mycophenolate in pregnancy a high number of fetal losses and a specific pattern of birth defects consisting of microtia, cleft lip, and other anomalies have been reported. However, so far, prospective data on pregnancy outcome allowing quantitative risk assessment are missing. We report on 57 prospectively ascertained pregnancies after maternal therapy with mycophenolate (mycophenolate mofetil or mycophenolate sodium) identified by European Teratology Information Services (ETIS) through their risk consultation process. The outcome of these prospective pregnancies was as follows: 16 spontaneous abortions, 12 elective terminations of pregnancy (ETOP) (including two late terminations for multiple malformations consistent with mycophenolate embryopathy), and 29 liveborn infants. The probability of spontaneous abortion was about 45% (95% CI 29 to 66%) estimated using survival analysis technique. Six out of 29 live born infants had major congenital defects: Two with external auditory canal atresia (EACA) (with and without microtia), one with tracheo-esophageal atresia, one with severe hydronephrosis, one with an atrial septal defect (ASD) and one with a myelomeningocele. Thus, at least four fetuses/infants of our prospective case series had a clinical phenotype consistent with mycophenolate embryopathy. Our results confirm a high incidence of major malformations (26%) after first trimester exposure to mycophenolate. Apart from exposure to mycophenololate, the underlying maternal disease and concomitant medication may also have contributed to the other poor pregnancy outcomes such as a high rate of spontaneous abortions, prematurity (62%), and low birth weight (31%).

Megalencephaly-capillary malformation (MCAP) and megalencephaly-polydactyly-polymicrogyria-hydrocephalus (MPPH) syndromes: two closely related disorders of brain overgrowth and abnormal brain and body morphogenesis.

Abstract: The macrocephaly-capillary malformation syndrome (M-CM), which we here propose to rename the megalencephaly-capillary malformation syndrome (MCAP; alternatively the megalencephaly-capillary malformation-polymicrogyria syndrome), and the more recently described megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH) are two megalencephaly (MEG) disorders that involve a unique constellation of physical and neuroimaging anomalies. We compare the features in 42 patients evaluated for physical and neuroimaging characteristics of MCAP and MPPH and propose a more global view of these syndromes based on classes of developmental abnormalities that include primary MEG and growth dysregulation, developmental vascular anomalies (primarily capillary malformations), distal limb anomalies (such as syndactyly and polydactyly), cortical brain malformations (most distinctively polymicrogyria, PMG), and variable connective tissue dysplasia. Based on these classes of developmental abnormalities, we propose that MCAP diagnostic criteria include progressive MEG with either vascular anomalies or syndactyly. In parallel, we propose that MPPH diagnostic criteria include progressive MEG and PMG, absence of the vascular anomalies and syndactyly characteristic of MCAP, and absence of brain heterotopia. © 2012 Wiley Periodicals, Inc.

“I want to know what's in Pandora's box”: Comparing stakeholder perspectives on incidental findings in clinical whole genomic sequencing†‡

Abstract: Whole genomic sequencing (WGS) promises significant personalized health benefits, and its increasingly low cost makes wide clinical use inevitable. However, a core challenge is “incidental findings” (IF). Using focus groups, we explored attitudes about the disclosure of IF in clinical settings from three perspectives: Genetics health-care professionals, the general public, and parents whose children have experienced genetic testing. Analysis was based on a framework approach. All three groups considered practical and ethical considerations. There was consensus that IF presented challenges for disclosure and a pre-test patient–clinician discussion was vital for clarification and agreement. The professionals favored targeted analysis to limit data handling and focus pre-test discussions on medical relevance. Their perspective highlighted ethical concepts of justice and beneficence. The lay groups' standpoint emphasized autonomy and patients' rights to choose what findings they receive, and that patients accept the consequences of any potential anxiety and uncertainty. The lay groups also felt that it was their responsibility to check genomic developments over time with their original test results and saw patient responsibility as an important part of patient choice. © 2012 Wiley Periodicals, Inc.

Management of pain and fatigue in the joint hypermobility syndrome (a.k.a. Ehlers-Danlos syndrome, hypermobility type): principles and proposal for a multidisciplinary approach.

Abstract: Joint hypermobility syndrome (JHS), or Ehlers-Danlos syndrome (EDS) hypermobility type (EDS-HT), is a underdiagnosed heritable connective tissue disorder characterized by generalized joint hypermobility and a wide range of visceral, pelvic, neurologic, and cognitive dysfunctions. Deterioration of quality of life is mainly associated with pain and fatigue. Except for the recognized effectiveness of physiotherapy for some musculoskeletal features, there are no standardized guidelines for the assessment and treatment of pain and fatigue. In this work, a practical classification of pain presentations and factors contributing in generating painful sensations in JHS/EDS-HT is proposed. Pain can be topographically classified in articular limb (acute/subacute and chronic), muscular limb (myofascial and fibromyalgia), neuropathic limb, back/neck, abdominal and pelvic pain, and headache. For selected forms of pain, specific predisposing characteristics are outlined. Fatigue appears as the result of multiple factors, including muscle weakness, respiratory insufficiency, unrefreshing sleep, dysautonomia, intestinal malabsorption, reactive depression/anxiety, and excessive use of analgesics. A set of lifestyle recommendations to instruct patients as well as specific investigations aimed at characterizing pain and fatigue are identified. Available treatment options are discussed in the set of a structured multidisciplinary approach based on reliable outcome tools.

Informed consent for whole genome sequencing: A qualitative analysis of participant expectations and perceptions of risks, benefits, and harms

Abstract: Scientific evidence on the extent to which ethical concerns about privacy, confidentiality, and return of results for whole genome sequencing (WGS) are effectively conveyed by informed consent (IC) is lacking. The aim of this study was to learn, via qualitative interviews, about participant expectations and perceptions of risks, benefits, and harms of WGS. Participants in two families with Miller syndrome consented for WGS were interviewed about their experiences of the IC process and their perceptions of risks, benefits, and harms of WGS. Interviews were transcribed and analyzed for common themes. IC documents are included in the Supplementary Materials. Participants expressed minimal concerns about privacy and confidentiality with regard to both their participation and sharing of their WGS data in restricted access databases. Participants expressed strong preferences about how results should be returned, requesting both flexibility of the results return process and options for the types of results to be returned. Participant concerns about risks to privacy and confidentiality from broad sharing of WGS data are likely to be strongly influenced by social and medical context. In these families with a rare Mendelian syndrome, the perceived benefits of participation strongly trumped concerns about risks. Individual preferences, for results return, even within a family, varied widely. This underscores the need to develop a framework for results return that allows explicitly for participant preferences and enables modifications to preferences over time. Web-based tools that facilitate participant management of their individual research results could accommodate such a framework. © 2012 Wiley Periodicals, Inc.

Antiepileptic drugs and pregnancy outcomes

Abstract: The treatment of epilepsy in women of reproductive age remains a clinical challenge. While most women with epilepsy (WWE) require anticonvulsant drugs for adequate control of their seizures, the teratogenicity associated with some antiepileptic drugs (AEDs) is a risk that needs to be carefully addressed. Antiepileptic medications are also used to treat an ever broadening range of medical conditions such as bipolar disorder, migraine prophylaxis, cancer, and neuropathic pain. Despite the fact that the majority of pregnancies of WWE who are receiving pharmacological treatment are normal, studies have demonstrated that the risk of having a pregnancy complicated by a major congenital malformation is doubled when comparing the risk of untreated pregnancies. Furthermore, when AEDs are used in polytherapy regimens, the risk is tripled, especially when valproic acid (VPA) is included. However, it should be noted that the risks are specific for each anticonvulsant drug. Some investigations have suggested that the risk of teratogenicity is increased in a dose-dependent manner. More recent studies have reported that in utero exposure to AEDs can have detrimental effects on the cognitive functions and language skills in later stages of life. In fact, the FDA just issued a safety announcement on the impact of VPA on cognition (Safety Announcement 6-30-2011). The purpose of this document is to review the most commonly used compounds in the treatment of WWE, and to provide information on the latest experimental and human epidemiological studies of the effects of AEDs in the exposed embryos.

Non-immune hydrops fetalis: A short review of etiology and pathophysiology

Abstract: Hydrops fetalis is an excessive accumulation of fetal fluid. Hydrops is traditionally classified into either immune or non-immune hydrops (NIHF), but in practice, nowadays in the Western world >90% of hydrops is of non-immune origin. The basis of the disorder is an imbalance in the regulation of fetal fluid movement between the vascular and interstitial space. We previously suggested a diagnostic flow-chart for NIHF. In this short review we describe the main mechanisms leading to NIHF.

The Centers for Mendelian Genomics: a new large-scale initiative to identify the genes underlying rare Mendelian conditions.

Abstract: In science and medicine there are occasional major advances that facilitate transformations of a field. The application of next-generation massively parallel sequencing technologies coupled with powerful computational approaches to discover genes for Mendelian disorders is arguably such a major advance [Biesecker, 2010]. Just three years ago, the strategy of exome sequencing (ES) followed by discrete filtering was introduced and shown to be a potential approach to identify the genes underlying Mendelian conditions [Choi et al., 2009; Ng et al., 2010; Ng et al., 2009]. Since then, ES and whole genome sequencing (WGS) [Lupski et al., 2010] have been used to explain the cause of dozens of disorders [Bamshad et al., 2011; Claudia Gonzaga-Jauregui, 2012; Gilissen et al., 2011] including those transmitted as X-linked, autosomal recessive [Bilguvar and et al., 2010], and autosomal dominant traits [Choi et al. 2011]; as well as phenotypes caused by de novo dominant mutations [Choate et al. 2010; O'Roak et al. 2011; Vissers et al. 2010] and somatic mosaicism [Lindhurst et al. 2011]. Given the technical and analytical improvements expected over the next several years, the application of ES/WGS-based strategies will enable the identification of the genes underlying a very large fraction of all known Mendelian disorders for which the genetic basis is not yet known — at a small fraction of the current cost for discovery per disorder. Based on these advances, exploring all Mendelian disorders should become an imperative for the worldwide human genetics community. The discoveries made through such exploration would be of enormous service to families, and will provide novel entry points to investigate the mechanisms underlying disease development. Such an effort would, however, be very ambitious, requiring an unprecedented degree of cooperation and coordination in the field of medical genetics and the assistance of patients and families from around the world. A global initiative to explore all Mendelian conditions is now emerging. The initiative, which includes the International Rare Diseases Research Consortium, the Finding of Rare Disease Genes (FORGE) in Canada, and centers in Europe, East Asia and elsewhere, will establish the necessary collaborative framework and physical infrastructure to achieve this goal. In the United States, the National Human Genome Research Institute (NHGRI) and the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) have partnered to support this effort at three Centers for Mendelian Genomics (CMGs): the Center for Mendelian Genomics at the University of Washington; the Center for Mendelian Disorders at Yale University; and the Baylor-Johns Hopkins Center for Mendelian Genomics at Baylor College of Medicine and the Johns Hopkins University. The CMGs have four major goals: (1) to ascertain samples for all Mendelian disorders for which the genetic basis is not yet understood from clinicians and investigators around the world by developing a ‘public list’ of samples and by coordinating submissions to the NIH program with those of other international programs; (2) to improve the efficiency of the sequencing pipeline and quality of exome and genome data through ongoing technology innovation; (3) to determine the genetic basis for as many Mendelian conditions as possible; and (4) to disseminate methods and data to facilitate gene discovery by investigators working independently across the globe. The CMGs will study disorders with age of onset across the entire lifespan including well-delineated, known Mendelian phenotypes as well as novel phenotypes thought to be Mendelian on the basis of their segregation patterns in families. Initially, the “public list” will be a catalog of collected DNA samples, organized by condition, that have entered the sequencing pipeline at any one of the CMGs. Next, this list will expand to include all of the Mendelian disorders for which the CMGs have solicited DNA samples, sequencing status, and the results obtained to date. Since the availability of a sufficient number of samples from clinically well-characterized cases and families will be critical to the discovery of genes for all Mendelian disorders, one aim of the public list is to facilitate coordination of sample collection and implementation of ES among clinicians and researchers around the world. Ultimately, the CMGs aim to develop the list into a comprehensive community resource that provides information on samples that are available worldwide for concerted disease gene discovery efforts. With this introduction, we would like to engage the medical genetics community to join with us and collaborate with the CMGs by submitting information about familial conditions, adding samples to the effort from individuals or families with rare Mendelian disorders to stimulate collaborations and eventually new insights. Since many of these conditions are rare, and often with locus heterogeneity, multiple investigators will need to contribute samples from individuals and families with the same diagnosis to improve chances for finding and validating candidate genes and variants. Following sequencing and analysis, the CMGs will return the results to the submitters, and will collaborate with investigators to facilitate further analysis, functional studies, and, ultimately publication. Results will be provided to the collaborating investigators as soon as possible. Collaborating investigators will have data exclusivity for a minimum of six months to ensure ample time to conduct follow up studies and prepare manuscripts for publication. The development of a public list will ensure transparency and facilitate communications about progress within and beyond the medical genetics community; this list will soon be accessible via the CMG website (http://mendelian.org). While the workflow will vary among CMGs, several key common practices across the CMGs will enable high-quality data production and analysis with partnering contributors. Phenotypic information associated with each sample and family will be collected and evaluated to increase diagnostic precision, identify phenotypic features that clarify genetic heterogeneity and aid in the identification of previously unrecognized disorders. DNA samples will be genotyped using low-cost, genome-wide marker arrays to provide a unique profile for sample tracking, to identify copy number variation (CNVs) and to provide genetic information for subsequent analysis of sequence variations (large and small insertion-deletions) underlying these conditions. These approaches, when applied to well-characterized pedigrees, will aid in finding the genomic intervals shared among all (or nearly all) cases, and reduce the genomic search space and speed the subsequent identification of candidate gene(s) by the collaborating investigators [Sobreira et al., 2010]. The success of this effort will require collaboration at an unprecedented scale in the field of human genetics. The CMGs and their global partners welcome partnering scientists and clinicians with samples or families affected with a Mendelian condition to collaborate with us by submitting inquiries to gro.nailednem@lednemg. The CMGs have partnered with Wiley-Liss and the American Journal of Medical Genetics (AJMG) to advertise in each issue to its worldwide readership of clinical and medical geneticists. The corresponding author of each manuscript accepted by the Journal will be provided with information about the CMGs. This is a welcome and important partnership since the AJMG is a well-known forum for the delineation of new syndromes and for reporting the description of novel rare, Mendelian conditions. Similarly, the Online Mendelian Inheritance in Man (OMIM; www.OMIM.org) catalog will provide a means for quickly disseminating summaries of newly discovered genes for known Mendelian disorders and adding newly delineated disorders to the OMIM catalog. We welcome the possibilities for other scientists, international journals and websites to link to the CMG site (http://mendelian.org). We ask clinicians and scientists to collaborate with us by submitting cases and families. The key drivers for the CMGs are to serve the scientific community and the individuals and families with rare diseases by improving knowledge about these rare conditions. By making specific diagnoses and exploring on a genome level the relationships between sequence variation and phenotype, collaboratively we can achieve more comprehensive pre-symptomatic or carrier screening. Additionally, the knowledge obtained from these efforts could initiate the exploration of new and/or improved therapeutics for these conditions. The CMG mechanism will eliminate significant financial and technical barriers for clinicians who wish to gain deeper understanding of genetic disorders and will catalyze interactions across the worldwide biomedical community to utilize these genotype/phenotype correlations to drive a deeper understanding of the biology of disease. The application of powerful new genomic approaches in genetics will provide an unprecedented view into the molecular basis of many, if not most, unexplained Mendelian phenotypes. The CMG will provide the community with access to production infrastructure, bioinformatics support, and analytical expertise. The challenge to the human genetics community is to help initiate this new phase of medical genomics and take advantage of this new opportunity by providing the resources for such studies that obviously cannot occur without finding and characterizing the patients and their families. Please contact us at gro.nailednem@lednemg or through the web portals of the individual centers with questions or with samples to submit.

Consensus Recommendations for Current Treatments and Accelerating Clinical Trials for Patients with Neurofibromatosis Type 2

Abstract: Neurofibromatosis type 2 (NF2) is a tumor suppressor syndrome characterized by bilateral vestibular schwannomas (VS) which often result in deafness despite aggressive management. Meningiomas, ependymomas, and other cranial nerve and peripheral schwannomas are also commonly found in NF2 and collectively lead to major neurologic morbidity and mortality. Traditionally, the overall survival rate in patients with NF2 is estimated to be 38% at 20 years from diagnosis. Hence, there is a desperate need for new, effective therapies. Recent progress in understanding the molecular basis of NF2 related tumors has aided in the identification of potential therapeutic targets and emerging clinical therapies. In June 2010, representatives of the international NF2 research and clinical community convened under the leadership of Drs. D. Gareth Evans (University of Manchester) and Marco Giovannini (House Research Institute) to review the state of NF2 treatment and clinical trials. This manuscript summarizes the expert opinions about current treatments for NF2 associated tumors and recommendations for advancing therapies emerging from that meeting. The development of effective therapies for NF2 associated tumors has the potential for significant clinical advancement not only for patients with NF2 but for thousands of neuro-oncology patients afflicted with these tumors.

The Barth Syndrome Registry: distinguishing disease characteristics and growth data from a longitudinal study.

Abstract: Barth syndrome (BTHS); MIM accession # 302060) is a rare X-linked recessive cardioskeletal mitochondrial myopathy with features of cardiomyopathy, neutropenia, and growth abnormalities. The objectives of this study were to further elucidate the natural history, clinical disease presentation, and course, and describe growth characteristics for males with BTHS. Patients with a confirmed genetic diagnosis of BTHS are referred to the BTHS Registry through the Barth Syndrome Foundation, self-referral, or physician referral. This study is based on data obtained from 73 subjects alive at the time of enrollment that provided self-reported and/or medical record abstracted data. The mean age at diagnosis of BTHS was 4.04 ± 5.45 years. While the vast majority of subjects reported a history of cardiac dysfunction, nearly 6% denied any history of cardiomyopathy. Although most subjects had only mildly abnormal cardiac function by echocardiography reports, 70% were recognized as having cardiomyopathy in the first year of life and 12% have required cardiac transplantation. Of the 73 enrolled subjects, there have been five deaths. Growth curves were generated demonstrating a shift down for weight, length, and height versus the normative population with late catch up in height for a significant percentage of cases. This data also confirms a significant number of patients with low birth weight, complications in the newborn period, failure to thrive, neutropenia, developmental delay of motor milestones, and mild learning difficulties. However, it is apparent that the disease manifestations are variable, both over time for an individual patient and across the BTHS population.

Renal anomalies in Alagille syndrome: A disease-defining feature†‡§

Abstract: Alagille syndrome (ALGS) is an autosomal dominant condition, primarily caused by mutations in JAGGED1. ALGS is defined by cholestatic liver disease, cardiac disease and involvement of the face, skeleton, and eyes with variable expression of these features. Renal involvement has been reported though not formally described. The objective of this study was to systematically characterize the renal involvement in ALGS. We performed a retrospective review of 466 JAGGED1 mutation-positive ALGS patients. Charts were reviewed for serum biochemistries, renal ultrasounds or other imaging, urinalysis, and clinical reports from pediatric nephrologists. The clinical data were reviewed by two pediatric hepatologists and a pediatric nephrologist. Of 466 charts reviewed we found 187 yielded evaluable renal information. Of these, 73/187 were shown to have renal involvement, representing 39% of the study cohort. Renal dysplasia was the most common anomaly seen. Genotype analysis of the JAGGED1 mutations in the patients with and without renal involvement did not reveal an association with mutation type. From the study we concluded that renal involvement has a prevalence of 39% in ALGS in our evaluable patients. Renal dysplasia is the most common renal anomaly. This finding correlates with the known role of the Notch pathway in glomerular development. Since renal disease of the type seen in ALGS can impair growth and impact liver transplantation, there is a clear need for a prospective study of renal involvement in ALGS and the development of guidelines for evaluation and management. These data also suggest that renal involvement be considered the sixth defining criterion for ALGS.

Increased risk of breast cancer in women with NF1.

Abstract: Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder associated with increased risk for neoplasms. Two studies in the United Kingdom have indicated that women with NF1 (particularly women under 50) may also be at increased risk of breast cancer. No such study has been done to date in the United States. Chart review for breast cancer diagnoses was undertaken for 126 women with NF1 followed at Johns Hopkins who were 20 years of age or older. Four of 126 women who met eligibility criteria were diagnosed with breast cancer (3.2% over 15 years). The unadjusted standardized incidence ratio (SIR) for breast cancer in the NF1 population between the ages of 20 and 49 was 2.68 (P=0.076, 95% CI: 0.68-7.29) based on incidence rates of breast cancer in the general population taken from the Surveillance Epidemiology and End Results (SEER) database. The unadjusted SIR for women with NF1 ≥50 was 0.81 (P=0.84, 95% CI: 0.041-4.01). When adjusted for race, the rate of NF1 in the general population and time of diagnosis, the SIR was 4.41 (P=0.0049, 95% CI: 1.12-12.00) for women <50 versus 0.94 (P=0.95, 95% CI: 0.047-4.65) for women ≥50. The trend of a higher-than-expected number of breast cancer cases in women <50 with NF1 agrees with the prior studies from the literature. Cumulatively, the data suggests an increased risk of breast cancer for women with NF1 <50 years old, implying a need for closer surveillance and the establishment of screening guidelines for this patient population.

Immune-mediated disorders among women carriers of fragile X premutation alleles†‡

Abstract: The relative risk of immune-mediated disorders (IMDs) among women carrier of premutation alleles is estimated by a survey for IMDs among 344 carrier women (age 19 to 81 years; mean 46.35 and SD 12.60) and 72 controls (age 18 to 87 years; mean 52.40 and SD 15.40). One hundred fifty four (44.77%) women carrier had at least one IMD, as did 20 controls (27.78%). Among women carrier, autoimmune thyroid disorder was the most common (24.4%), then fibromyalgia (10.2%), irritable bowel syndrome (IBS; 9.9%), Raynaud’s phenomenon (7.6%), rheumatoid arthritis (RA; 3.8%), Sjogren syndrome (2.6%), systemic lupus erythematosus (SLE; 2.03%), multiple sclerosis (1.74%). Of 55 carriers age 40 or older with FXTAS, 72.73% had at least one IMD, compared to 46.54% of those without FXTAS (n=159), and 31.58% of controls (n=57). The estimated odds ratio (OR) for IMD is 2.6 (95% CI 1.2–5.6, p = 0.015) for women with FXTAS relative to those without FXTAS; the likelihood of IMD in carriers without or with FXTAS was also significantly higher than for controls (OR 2.1, 95% CI 1.1–4.2, p = 0.034; OR 5.5, 95% CI 2.4–12.5, p < 0.001 respectively). Similarly, the odds of having an IMD among carriers with FXPOI is about 2.4 times higher when compared to carriers without FXPOI (95% CI 1.1–5.0; p = 0.021). The likelihood of IMD in carriers with or without FXPOI is greater (OR 2.4, 95% CI 1.1–5.0; p = 0.021) compared to that of controls.

Long QT, Syndactyly, Joint Contractures, Stroke and Novel CACNA1C Mutation: Expanding the Spectrum of Timothy Syndrome

Abstract: Timothy syndrome (TS) is an autosomal dominant condition with the constellation of features including prolonged QT interval, hand and foot abnormalities, and mental retardation or autism. Splawski et al. [2004] previously described two phenotypes associated with TS distinguished by two unique and different mutations within the CACNA1C gene. We report on a newborn who presented with prolonged QT interval and associated polymorphic ventricular tachycardia, dysmorphic facial features, syndactyly of the hands and feet, and joint contractures, suggestive of TS. He developed a stroke, subsequent intractable seizures, and was found to have cortical blindness and later profound developmental delay. Initial targeted mutation analysis did not identify either of the previously described TS associated mutations; however, full gene sequencing detected a novel CACNA1C gene mutation (p.Ala1473Gly). The clinical and genetic findings in our case expand both the clinical and molecular knowledge of TS.

Biobank Participation and Returning Research Results: Perspectives from a Deliberative Engagement in South Side Chicago

Abstract: To be respectful of the public, biobank guiding principles and operations should be responsive to and inclusive of the values and beliefs of their participants. In an effort to increase knowledge and inform institutional policies, we conducted a deliberative engagement of individuals from two healthcare facilities in South Side Chicago that serve different socioeconomic communities to consider biobank policies regarding return of research results. We recruited primary caregivers of children receiving care at either a Federally Qualified Health Center or a university-based practice to attend two full-day deliberative engagement sessions, which included four educational presentations followed by focus group discussions. Surveys were administered to assess attitudes before and after the engagement, and an evaluation was conducted to assess the deliberative engagement process. All 45 participants self-identified as African-American. Focus group themes included: (1) overall interest in biobank participation, broad consent, and recontact; (2) root causes of distrust and potential biobank strategies to facilitate trust; (3) perceived positive and negative aspects of receiving research results; and (4) strong interest in receiving and managing their children's research results. Survey data indicated the same degree of interest in receiving results about themselves as about their children. Pre- and post-session findings showed mainly non-significant attitudinal changes in level of interest in biobank participation and return of research results, although there was a decrease in level of concern regarding identification from research data. Our findings reveal shared community insights important in facilitating relationships and policy discussions between biobank researchers and research participants.

Gynecologic and obstetric implications of the joint hypermobility syndrome (a.k.a. Ehlers-Danlos syndrome hypermobility type) in 82 Italian patients.

Abstract: Joint hypermobility syndrome (JHS) emerges as likely the most common clinical form of Ehlers-Danlos syndrome. Given the striking predominance of affected women, practitioners often face gynecologic and obstetric issues. However, their decisions are still based on personal experience rather than literature due to the lack of a consistent body of evidence. We collected a set of gynecologic and obstetric features in 82 post-puberal women with JHS attending two Italian centers. Common gynecologic findings were dysmenorrhea (82.9%), meno/metrorrhagias (53.7%), irregular menses (46.3%), and dispareunia/vulvodinia (31.7%). Forty women were nulliparous and 42 had one or more pregnancy for a total of 93 diagnosed conceptions. Of them, 16.1% were spontaneous abortions, 6.5% voluntary interruptions, 10.7% preterm deliveries, and 66.7% deliveries at term. Overall outcome of proceeding pregnancies was good with no stillbirth and fetal/neonatal hypoxic/ischemic event. Non-operative vaginal delivery was registered in 72.2%, forceps/vacuum use in 5.5% and cesarean in 22.3%. Local/total anesthesia was successfully performed in 17 pregnancies without any problem. Major post-partum complications included abnormal scar formation after cesarean or episiotomy (46.1%), hemorrhage (19.4%), pelvic prolapses (15.3%), deep venous thrombosis (4.2%), and coccyx dislocation (1.4%). Prolapses were the most clinically relevant complication and associated with episiotomy. Gathered data were discussed for practically oriented considerations.

Genome-wide SNP genotyping identifies the Stereocilin (STRC) gene as a major contributor to pediatric bilateral sensorineural hearing impairment†

Abstract: Hearing loss is the most prevalent sensory perception deficit in humans, affecting 1/500 newborns, can be syndromic or nonsyndromic and is genetically heterogeneous. Nearly 80% of inherited nonsyndromic bilateral sensorineural hearing loss (NBSNHI) is autosomal recessive. Although many causal genes have been identified, most are minor contributors, except for GJB2, which accounts for nearly 50% of all recessive cases of severe to profound congenital NBSNHI in some populations. More than 60% of children with a NBSNHI do not have an identifiable genetic cause. To identify genetic contributors, we genotyped 659 GJB2 mutation negative pediatric probands with NBSNHI and assayed for copy number variants (CNVs). After identifying 8 mild-moderate NBSNHI probands with a Chr15q15.3 deletion encompassing the Stereocilin (STRC) gene amongst this cohort, sequencing of STRC was undertaken in these probands as well as 50 probands and 14 siblings with mild-moderate NBSNHI and 40 probands with moderately severe-profound NBSNHI who were GJB2 mutation negative. The existence of a STRC pseudogene that is 99.6% homologous to the STRC coding region has made the sequencing interpretation complicated. We identified 7/50 probands in the mild-moderate cohort to have biallelic alterations in STRC, not including the 8 previously identified deletions. We also identified 2/40 probands to have biallelic alterations in the moderately severe-profound NBSNHI cohort, notably no large deletions in combination with another variant were found in this cohort. The data suggest that STRC may be a common contributor to NBSNHI among GJB2 mutation negative probands, especially in those with mild to moderate hearing impairment.

Clinical geneticists' views of VACTERL/VATER association.

Abstract: VACTERL association (sometimes termed "VATER association" depending on which component features are included) is typically defined by the presence of at least three of the following congenital malformations, which tend to statistically co-occur in affected individuals: Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheo-Esophageal fistula, Renal anomalies, and Limb abnormalities. Although the clinical criteria for VACTERL association may appear to be straightforward, there is wide variability in the way clinical geneticists define the disorder and the genetic testing strategy they use when confronted with an affected patient. In order to describe this variability and determine the most commonly used definitions and testing modalities, we present the results of survey responses by 121 clinical geneticists. We discuss the results of the survey responses, provide a literature review and commentary from a group of physicians who are currently involved in clinical and laboratory-based research on VACTERL association, and offer an algorithm for genetic testing in patients with this association.

Cytogenetic and epidemiological findings in Down syndrome: England and Wales 1989-2009

Abstract: This study describes the characteristics of karyotypes leading to phenotypic Down syndrome (trisomy 21) in 29,256 cases diagnosed between 1989 and 2009 in England and Wales included in the National Down Syndrome Cytogenetic Register (NDSCR). The frequency of occurrence of the different karyotypes, proportions diagnosed prenatally, sex ratios, mean maternal age, and proportions of mothers with recurrences were analyzed. Nearly 97% of all cases were free trisomy 21; 2.9% contributory trisomy 21, 0.3% double or triple aneuploidies; 1% of all were mosaics. Mean maternal age of free trisomy 21 cases was 35 years, 54% were male, and 1% of mothers had recurrences. Free trisomy 21 mosaics had a lower mean maternal age (33 years), a lower proportion of males (39.5%), and 2.5% of mothers had recurrences. The majority of contributory translocations were Robertsonian or rea (21;21). Their mothers were younger, particularly those of Robertsonian translocations (28 years). Of the Robertsonian der (14;21) translocations of known parental origin, 54% were de novo, 41% maternal and 5% paternal and 15.8% of mothers of those of maternal origin had recurrences. Multiple aneuploidies have the highest proportion of males (67%), highest proportion of mosaics (40%), a mean maternal age of 37 years, and no mothers had a recurrence. The size of this national register allowed the frequency of occurrence of the rarer karyotypes of Down syndrome to be estimated and their epidemiology described.

Novel clinical manifestations in Pallister–Killian syndrome: Comprehensive evaluation of 59 affected individuals and review of previously reported cases

Abstract: Pallister-Killian syndrome is a rare, multi-system developmental diagnosis typically caused by tetrasomy of chromosome 12p that exhibits tissue-limited mosaicism. The spectrum of clinical manifestations in Pallister-Killian syndrome is wide and includes craniofacial anomalies, clefts, ophthalmologic, audiologic, cardiac, musculoskeletal, diaphragmatic, gastrointestinal, genitourinary, and cutaneous anomalies in association with intellectual disability and seizures. Growth parameters are often normal to elevated at birth with deceleration of growth postnatally. No formal estimate of the prevalence of Pallister-Killian syndrome has been made. Here, we report the clinical findings in 59 individuals with Pallister-Killian syndrome who were ascertained at Pallister-Killian syndrome Foundation family meetings held in the summers of 2006, 2008, 2009, and 2010. In addition, the clinical findings of 152 cases reported in the medical literature were reviewed and compared to the cohort examined here. Several novel clinical characteristics were identified through detailed dysmorphology examinations of this cohort and reassertion of a mild developmental variant is described. This report expands the clinical manifestations of Pallister-Killian syndrome and highlights the variable expressivity of this diagnosis with important implications for diagnosis and counseling.

The evaluation of cascade testing for familial hypercholesterolemia.

Abstract: Familial hypercholesterolemia (FH) is an autosomal dominant disorder with a high risk of coronary heart disease at a young age that can be reduced by cholesterol-lowering drugs. Computer simulation was used to estimate the screening performance of three strategies of cascade testing for FH (a process of searching for relatives with FH once an individual is diagnosed with FH): (i) testing parents, siblings, and children (1st degree relatives) of an FH index case, (ii) testing (i) and testing 1st degree relatives of subsequently identified relatives with FH, and (iii) testing (ii) and also testing aunts, uncles, nephews, nieces, grandparents, and first cousins (2nd or 3rd degree relatives) when 1st degree relatives of an individual with FH are not available. For cascade testing to achieve detection rates of 80%, (i) 25%, (ii) 11%, and (iii) 8% of FH index cases who are unrelated need to be identified. To identify these unrelated FH index cases, (i) 45% (ii) 23%, and (iii) 17% of all individuals with FH need to be identified independently of cascade testing. Cascade testing is not a suitable method of population screening for FH, because a separate method of systematically identifying new FH index cases is required to achieve a reasonable level of FH detection in the population. Such an alternative systematic method of identifying new cases could itself be the method of population screening.

Consanguinity and the risk of congenital heart disease

Abstract: Consanguineous unions have been associated with an increased susceptibility to various forms of inherited disease. Although consanguinity is known to contribute to recessive diseases, the potential role of consanguinity in certain common birth defects is less clear, particularly since the disease pathophysiology may involve genetic and environmental/epigenetic factors. In this study, we ask whether consanguinity affects one of the most common birth defects, congenital heart disease, and identify areas for further research into these birth defects, since consanguinity may now impact health on a near-global basis. A systematic review of consanguinity in congenital heart disease was performed, focusing on non-syndromic disease, with the methodologies and results from studies of different ethnic populations compared. The risks for congenital heart disease have been assessed and summarized collectively and by individual lesion. The majority of studies support the view that consanguinity increases the prevalence of congenital heart disease, however, the study designs differed dramatically. Only a few (n = 3) population-based studies that controlled for potential sociodemographic confounding were identified, and data on individual cardiac lesions were limited by case numbers. Overall the results suggest that the risk for congenital heart disease is increased in consanguineous unions in the studied populations, principally at first-cousin level and closer, a factor that should be considered in empiric risk estimates in genetic counseling. However, for more precise risk estimates a better understanding of the underlying disease factors is needed.

XX male sex reversal with genital abnormalities associated with a de novo SOX3 gene duplication

Abstract: Differentiation of the bipotential gonad into testis is initiated by the Y chromosome-linked gene SRY (Sex-determining Region Y) through upregulation of its autosomal direct target gene SOX9 (Sry-related HMG box-containing gene 9). Sequence and chromosome homology studies have shown that SRY most probably evolved from SOX3, which in humans is located at Xq27.1. Mutations causing SOX3 loss-of-function do not affect the sex determination in mice or humans. However, transgenic mouse studies have shown that ectopic expression of Sox3 in the bipotential gonad results in upregulation of Sox9, resulting in testicular induction and XX male sex reversal. However, the mechanism by which these rearrangements cause sex reversal and the frequency with which they are associated with disorders of sex development remains unclear. Rearrangements of the SOX3 locus were identified recently in three cases of human XX male sex reversal. We report on a case of XX male sex reversal associated with a novel de novo duplication of the SOX3 gene. These data provide additional evidence that SOX3 gain-of-function in the XX bipotential gonad causes XX male sex reversal and further support the hypothesis that SOX3 is the evolutionary antecedent of SRY.

Medical complications, clinical findings, and educational outcomes in adults with Noonan syndrome.

Abstract: Noonan syndrome (NS) is a heterogeneous developmental disorder caused by missense mutations in genes involved in the Ras/MAPK signaling pathway, a major mediator of early and late developmental processes. The diagnosis of NS is made on clinical grounds with molecular confirmation of a mutation found in 63% of cases. Key clinical features include short stature, cardiac defects, developmental delay, lymphatic dysplasias, bleeding tendency, and a constellation of distinctive facial features and physical exam findings. The prevalence of medical issues or the development of new ones in adults with NS is not well-studied. This cross-sectional study reports on the prevalence of clinical conditions and their ages of onset in a cohort of 35 adolescents and adults with NS aged 16-68 years old (mean age 28 years). In this cohort, 34 of 35 subjects (97%) had had full PTPN11 sequencing; 37% were PTPN11 positive, 23% were SOS1 positive, and 3% were BRAF positive. Mean adult height in both men and women was at the 3rd-10th centile. The most prevalent clinical findings in this cohort included pulmonary valve stenosis (71%), easy bruising (63%), GERD (60%), constipation (51%), scoliosis (54%), chronic joint pain (54%), lymphedema (49%), depression (49%), anxiety (49%), Chiari malformation (20%), and osteopenia/osteoporosis (14%). In summary, adults with NS are affected by multi-organ morbidity and require special medical management aimed towards the most prevalent and serious known medical complications. Larger studies characterizing the clinical conditions found in NS adults are needed to provide potential genotype-phenotype correlations that may aid in clinical management.

Prevalence and clinical features of Costello syndrome and cardio-facio-cutaneous syndrome in Japan: findings from a nationwide epidemiological survey.

Abstract: Costello syndrome and cardio-facio-cutaneous (CFC) syndrome are congenital anomaly syndromes characterized by a distinctive facial appearance, heart defects, and intellectual disability. Germline mutations in HRAS cause Costello syndrome, and mutations in KRAS, BRAF, and MAP2K1/2 (MEK1/2) cause CFC syndrome. Since the discovery of the causative genes, approximately 150 new patients with each syndrome have been reported. However, the clinico-epidemiological features of these disorders remain to be identified. In order to assess the prevalence, natural history, prognosis, and tumor incidence associated with these diseases, we conducted a nationwide prevalence study of patients with Costello and CFC syndromes in Japan. Based on the result of our survey, we estimated a total number of patients with either Costello syndrome or CFC syndrome in Japan of 99 (95% confidence interval, 77-120) and 157 (95% confidence interval, 86-229), respectively. The prevalences of Costello and CFC syndromes are estimated to be 1 in 1,290,000 and 1 in 810,000 individuals, respectively. An evaluation of 15 adult patients 18-32 years of age revealed that 12 had moderate to severe intellectual disability and most live at home without constant medical care. These results suggested that the number of adult patients is likely underestimated and our results represent a minimum prevalence. This is the first epidemiological study of Costello syndrome and CFC syndrome. Identifying patients older than 32 years of age and following up on the patients reported here is important to estimate the precise prevalence and the natural history of these disorders.

Factors associated with perceived uncertainty among parents of children with undiagnosed medical conditions

Abstract: Uncertainty is a pervasive characteristic of illness. Yet little is known about the individual or situational factors that contribute to perceptions of uncertainty. The present study aims to examine the factors that contribute to perceived uncertainty among parents of a child with an undiagnosed condition. Two hundred sixty-six parents of a child, or children, affected by an undiagnosed medical condition for at least 2 years completed an electronically administered mixed-methods survey assessing theoretical predictors of perceived uncertainty. Multivariate linear regression analyses were used to identify the relationship of key variables to perceived uncertainty. Parents' perceived control and optimism were negatively associated with uncertainty (B=-4.044, P≤0.001, B=-0.477, P≤0.05). Subjective disease severity was positively associated with perceived uncertainty (B=1.797, P≤0.05). Our findings suggest that parents who experience greater uncertainty feel less control over their child's medical condition, which may lead to less effective coping and poorer adaptation. Parents who are less optimistic or who perceive their child's disease as more severe may benefit most from interventions that target situations where parents perceive the least control, thereby enhancing coping and ultimately, adaptation.

Nationwide survey of nevoid basal cell carcinoma syndrome in Japan revealing the low frequency of basal cell carcinoma.

Abstract: Nevoid basal cell carcinoma syndrome (NBCCS) is characterized by developmental defects and tumorigenesis. The clinical manifestations of NBCCS have been reported in large epidemiological studies from the United States, the United Kingdom, and Australia, but not from an Asian country. We conducted a nationwide survey and identified 311 NBCCS patients in Japan. We investigated the detailed clinical manifestations of 157 patients ranging in age from 9 months to 77 years old (mean: 33.1 years). We then compared the frequency and age of onset for various tumors developed in Japanese NBCCS patients with patients from the three countries listed above in which NBCCS studies were previously conducted. Our most significant finding was the low frequency of basal cell carcinoma (BCC) in Japanese patients. Frequency of BCC in patients over 20 years of age was 51.4%, a much lower rate compared to the United States, Australia, and the United Kingdom (91%, 85%, and 73%, respectively). The mean age of BCC onset was 37.4 years of age, a much older age compared to the above-mentioned countries. These findings suggest that differences in ethnicity and/or environmental factors affect the incidence of BCC. Because the age of BCC onset is generally higher in Japanese NBCCS patients, careful skin examination over a prolonged period of time is warranted.

Genotype-phenotype analysis of 4q deletion syndrome: proposal of a critical region.

Abstract: Chromosome 4q deletion syndrome (4q- syndrome) is a rare condition, with an estimated incidence of 1 in 100,000. Although variable, the clinical spectrum commonly includes craniofacial, developmental, digital, skeletal, and cardiac involvement. Data on the genotype–phenotype correlation within the 4q arm are limited. We present detailed clinical and genetic information by array CGH on 20 patients with 4q deletions. We identified a patient who has a ∼465 kb deletion (186,770,069–187,234,800, hg18 coordinates) in 4q35.1 with all clinical features for 4q deletion syndrome except for developmental delay, suggesting that this is a critical region for this condition and a specific gene responsible for orofacial clefts and congenital heart defects resides in this region. Since the patients with terminal deletions all had cleft palate, our results provide further evidence that a gene associated with clefts is located on the terminal segment of 4q. By comparing and contrasting our patients' genetic information and clinical features, we found significant genotype–phenotype correlations at a single gene level linking specific phenotypes to individual genes. Based on these data, we constructed a hypothetical partial phenotype-genotype map for chromosome 4q which includes BMP3, SEC31A, MAPK10, SPARCL1, DMP1, IBSP, PKD2, GRID2, PITX2, NEUROG2, ANK2, FGF2, HAND2, and DUX4 genes. © 2012 Wiley Periodicals, Inc.

Balanced complex chromosome rearrangements: reproductive aspects. A review.

Abstract: This review examines the reproductive consequences for carriers of a balanced complex chromosome rearrangement (CCR). It is based on an analysis of CCRs in 103 adults referred for reproductive problems, including male infertility. The main focus is on reproductive risks based on data from 84 CCRs. Carriers of balanced CCRs have a high risk of an abortion and/or a chromosomally unbalanced child. I have identified roughly four different types of CCRs (I–IV); most (44%) belong to Type I with a simple 3-way or 4-way exchange of segments and risk factors similar to those for reciprocal translocations. There were only three CCRs (4%) of type II, which involve an inversion. Type III CCRs (21%) involve one or more insertions with ∼35% risk of a child with a duplication or a deletion of the inserted segment. Type IV CCRs (31%) involve a “middle segment” in a derivative chromosome with segments from at least three chromosomes. In ∼35% of these CCRs, recombination occurs in this segment, which can produce imbalance but in many cases it changes a CCR into a simpler balanced rearrangement in the next generation. Balanced CCRs, which have been often considered together in one group, can now be split into four types, each with a risk of a different type of imbalance. This analysis provides a better understanding of the reproductive consequences for carriers of balanced CCRs and should be useful in prenatal diagnosis and genetic counseling. © 2012 Wiley Periodicals, Inc.