Showing papers in "American Journal of Medical Genetics in 1997"

Clinical manifestations in 105 persons with nevoid basal cell carcinoma syndrome.

Abstract: Nevoid basal cell carcinoma syndrome (NBCC; Gorlin syndrome), an autosomal dominant disorder linked to 9q22.3-q31, and caused by mutations in PTC, the human homologue of the Drosophila patched gene, comprises multiple basal cell carcinomas, keratocysts of the jaw, palmar/plantar pits, spine and rib anomalies and calcification of the falx cerebri. We reviewed the findings on 105 affected individuals examined at the NIH since 1985. The data included 48 males and 57 females ranging in age from 4 months to 87 years. Eighty percent of whites (71/90) and 38% (5/13) of African-Americans had at least one basal cell carcinoma (BCC), with the first tumor occurring at a mean age of 23 (median 20) years and 21 (median 20) years, respectively. Excluding individuals exposed to radiation therapy, the number of BCCs ranged from 1 to >1,000 (median 8) and 1 to 3 (median 2), respectively, in the 2 groups. Jaw cysts occurred in 78/105 (74%) with the first tumor occurring in 80% by the age of 20 years. The number of total jaw cysts ranged from 1 to 28 (median 3). Palmar pits and plantar pits were seen in 87%. Ovarian fibromas were diagnosed by ultrasound in 9/52 (17%) at a meanmore » age of 30 years. Medulloblastoma occurred in 4 patients at a mean age of 2.3 years. Three patients had cleft lip or palate. Physical findings include {open_quotes}coarse face{close_quotes} in 54%, relative macrocephaly in 50%, hypertelorism in 42%, frontal bossing in 27%, pectus deformity in 13%, and Sprengel deformity in 11%. This study delineates the frequency of the clinical and radiological anomalies in NBCC in a large population of US patients and discusses guidelines for diagnosis and management. 48 refs., 3 figs., 5 tabs.« less

Evaluation of mental retardation: Recommendations of a consensus conference

Abstract: A Consensus Conference utilizing available literature and expert opinion sponsored by the American College of Medical Genetics in October 1995 evaluated the rational approach to the individual with mental retardation. Although no uniform protocol replaces individual clinician judgement, the consensus recommendations were as follows: 1. The individual with mental retardation, the family, and medical care providers benefit from a focused clinical and laboratory evaluation aimed at establishing causation and in providing counseling, prognosis, recurrence risks, and guidelines for management. 2. Essential elements of the evaluation include a three-generation pedigree: pre-, peri-, and post-natal history, complete physical examination focused on the presence of minor anomalies, neurologic examination, and assessment of the behavioral phenotype. 3. Selective laboratory testing should, in most patients, include a banded karyotype. Fragile X testing should be strongly considered in both males and females with unexplained mental retardation, especially in the presence of a positive family history, a consistent physical and behavioral phenotype and absence of major structural abnormalities. Metabolic testing should be initialed in the presence of suggestive clinical and physical findings. Neuroimaging should be considered in patients without a known diagnosis especially in the presence of neurologic symptoms, cranial contour abnormalities, microcephaly, or macrocephaly. In most situations MRI is the testing modality of choice. 4. Sequential evaluation of the patient, occasionally over several years, is often necessary for diagnosis, allowing for delineation of the physical and behavioral phenotype, a logical approach to ancillary testing and appropriate prognostic and reproductive counseling.

Type 1 neurofibromatosis: a descriptive analysis of the disorder in 1,728 patients

Abstract: Type 1 Neurofibromatosis, NF1, is a common genetic disorder with variable clinical manifestations. Although NF1 often is only of cosmetic concern, serious and even lethal complications may occur. It is not possible to predict which symptoms will develop in any affected individual. The NNFF International Database is a multicentre collaborative system for collecting information about this condition. At the time of this analysis, complete clinical information was available on 1,479 probands and 249 of their affected relatives with NF1. On average, the age at diagnosis of NF1 was 8 years younger in the probands than in the affected relatives (P<.01). Many of the manifestations of NF1 were more frequent in the probands than in their affected relatives. The age-specific prevalence of most manifestations of NF1 increases with age. Despite biases inherent in a convenience sample from specialist clinics, the frequencies of many of the serious manifestations of NF1 are similar to those of two smaller population-based studies. The frequencies in this study are likely representative of patients seen at specialized clinics.

Xq28-linked noncompaction of the left ventricular myocardium : prenatal diagnosis and pathologic analysis of affected individuals

Abstract: Isolated noncompaction of the left ventricular myocardium (INVM) is characterized by the presence of numerous prominent trabeculations and deep intertrabecular recesses within the left ventricle, sometimes also affecting the right ventricle and interventricular septum. Familial occurrence of this disorder was described previously. We present a family in which 6 affected individuals demonstrated X-linked recessive inheritance of this trait. Affected relatives presented postnatally with left ventricular failure and arrhythmias, associated with the pathognomonic echocardiographic findings of INVM. The usual findings of Barth syndrome (neutropenia, growth retardation, elevated urinary organic acids, low carnitine levels, and mitochondrial abnormalities) were either absent or found inconsistently. Fetal echocardiograms obtained between 24-30 weeks of gestation in 3 of the affected males showed a dilated left ventricle in one heart, but were not otherwise diagnostic of INVM in any of the cases. Four of the affected individuals died during infancy, one is in cardiac failure at age 8 months, and one is alive following cardiac transplant at age 9 months. The hearts from infants who died or underwent transplantation appeared, on gross examination, to be enlarged, with coarse, deep ventricular trabeculations and prominent endocardial fibroelastosis. Histologically, there were loosely organized fascicles of myocytes in subepicardial and midmyocardial zones of both ventricles, and the myocytes showed thin, often angulated fibers with prominent central clearing and reduced numbers of filaments. Markedly elongated mitochondria were present in some ventricular myocytes from one specimen, but this finding was not reproducible. Genetic linkage analysis has localized INVM to the Xq28 region, where other myopathies with cardiac involvement have been located.

Personality and language characteristics in parents from multiple‐incidence autism families

Abstract: Several studies have suggested that the genetic liability for autism may be expressed in non-autistic relatives of autistic probands, in behavioral characteristics that are milder but qualitatively similar to the defining features of autism. We employ a variety of direct assessment approaches to examine both personality and language in parents ascertained through having two autistic children (multiple-incidence autism parents) and parents of Down syndrome probands. Multiple-incidence autism parents had higher rates of particular personality characteristics (rigidity, aloofness, hypersensitivity to criticism, and anxiousness), speech and pragmatic language deficits, and more limited friendships than parents in the comparison group. The implications of these findings for future genetic studies of autism are discussed.

Family history: A comprehensive genetic risk assessment method for the chronic conditions of adulthood

Abstract: Targeting individuals with increased risk for common, chronic disease can improve the efficiency and efficacy of preventive efforts by improving the predictability of screening tests and participant compliance. Individuals with the greatest risk for these disorders are those with a genetic susceptibility. The purpose of this study was to determine the feasibility of using a single, comprehensive family history as a method for stratifying risk for many preventable, common genetic disorders. Family histories obtained in a prenatal diagnostic clinic were reviewed regarding cardiovascular diseases, diabetes and several cancers; 42.5% of individuals reported a family history for at least one of the disorders under study. Familial coronary artery disease was most commonly reported (29% of participants), followed by noninsulin-dependent diabetes (14%). Qualitative characterization of disease susceptibility was also accomplished using family history data. For example, occurrence of different cancers within pedigrees was suggestive of familial cancer syndromes, and clustering of noninsulin-dependent diabetes and cardiovascular disease suggested an insulin resistance syndrome. Depending on the specific disease, 5 to 15% of at-risk individuals had a moderately increased risk (2 to 5 times the population risk), and approximately 1 to 10% had a high risk (absolute risks approaching 50%). Family history reports of common, chronic disease are prevalent among the population at large, and collection and interpretation of comprehensive family history data is a feasible, initial method for risk stratification for many preventable, chronic conditions. These findings may have important implications for disease prevention and management.

The spectrum of congenital anomalies of the VATER association: An international study

Abstract: The spectrum of the VATER association has been debated ever since its description more than two decades ago. To assess the spectrum of congenital anomalies associated with VATER while minimizing the distortions due to small samples and referral patterns typical of clinical series, we studied infants with VATER association reported to the combined registry of infants with multiple congenital anomalies from 17 birth defects registries worldwide that are part of the International Clearinghouse for Birth Defects Monitoring Systems (ICB-DMS). Among approximately 10 million infants born from 1983 through 1991, the ICB-DMS registered 2,295 infants with 3 or more of 25 unrelated major congenital anomalies of unknown cause. Of these infants, 286 had the VATER association, defined as at least three of the five VATER anomalies (vertebral defects, anal atresia, esophageal atresia, renal defects, and radial-ray limb deficiency), when we expected 219 (P<0.001). Of these 286 infants, 51 had at least four VATER anomalies, and 8 had all five anomalies. We found that preaxial but not other limb anomalies were significantly associated with any combination of the four nonlimb VATER anomalies (P<0.001). Of the 286 infants with VATER association, 214 (74.8%) had additional defects. Genital defects, cardiovascular anomalies, and small intestinal atresias were positively associated with VATER association (P<0.001). Infants with VATER association that included both renal anomalies and anorectal atresia were significantly more likely to have genital defects. Finally, a subset of infants with VATER association also had defects described in other associations, including diaphragmatic defects, oral clefts, bladder exstrophy, omphalocele, and neural tube defects. These results offer evidence for the specificity of the VATER association, suggest the existence of distinct subsets within the association, and raise the question of a common pathway for patterns of VATER and other types of defects in at least a subset of infants with multiple congenital anomalies.

Clinical and biochemical spectrum of patients with RSH/Smith-Lemli-Opitz syndrome and abnormal cholesterol metabolism

Abstract: RSH/Smith-Lemli-Opitz (RSH/SLO) syndrome is an autosomal recessive malformation syndrome recently shown to be associated with a severe deficiency of cholesterol biosynthesis and markedly elevated plasma and tissue levels of 7-dehydrocholesterol (7-DHC), the immediate precursor of cholesterol in the Kandutsch-Russell biosynthetic pathway. Because these biochemical abnormalities permit a reassessment of RSH/SLO on biochemical criteria rather than less specific physical criteria, we review here the clinical and biochemical characteristics of our first 80 patients with abnormally increased levels of 7-DHC. The study population included 68 index patients and 12 additional relatives identified by quantification of 7-DHC and cholesterol in plasma, amniotic fluid, or cultured fibroblasts, lymphoblasts, or amniocytes. As demonstrated in other clinical syndromes when redefined biochemically, we have found a wider range of clinical expression of RSH/SLO than previously recognized. These newly recognized atypical RSH/SLO patients included several with no malformations other than syndactyly of the toes and, at the other extreme, patients with frank holoprosencephaly or multiple visceral anomalies who died in utero. Syndactyly of toes 2 and 3 was the most common malformation, occurring in all but one of 80 patients. The best biochemical predictor of clinical severity was the plasma cholesterol level, which decreased with increasing clinical severity. However, at least 10% of patients, including one newborn infant, had normal cholesterol levels at the time of diagnosis and would have been missed without specific quantification of 7-DHC. Not unexpectedly, several patients carrying a clinical diagnosis of RSH/SLO were found to have normal levels of all plasma sterols and apparently normal cholesterol biosynthesis in cultured cells. A comparison of the frequency of anomalies in our biochemically identified patients with similar data from previously reported clinical series suggests that up to 25% of reports of RSH/SLO in the literature may describe genetic conditions other than RSH/SLO with 7-DHC-emia.

Initial genome scan of the NIMH genetics initiative bipolar pedigrees: chromosomes 1, 6, 8, 10, and 12.

Abstract: A report on an initial genome screen on 540 individuals in 97 families was collected as part of the NIMH Genetics Initiative on Bipolar Disorder. Families were ascertained to be informative for genetic linkage and underwent a common ascertainment and assessment protocol at four clinical sites. The sample was genotyped for 65 highly polymorphic markers from chromosomes 1, 6, 8, 10, and 12. The average intermarker interval was 16 cM. Genotypic data was analyzed using affected sib pair, multipoint affected sib pair, and pedigree analysis methods. Multipoint methods gave lod scores of approximately two on chromosomes 1, 6, and 10. The peak lod score on chromosome 6 occurred at the end of the q-arm, at some distance from the 6p24-22 area previously implicated for schizophrenia. We are currently genotyping additional markers to reduce the intermarker interval around the signals. The interpretation of results from a genome screen of a complex disorder and the problem of achieving a balance between detecting false positive results and the ability to detect genes of modest effect are discussed.

Comparison of phenotype between patients with Prader-Willi syndrome due to deletion 15q and uniparental disomy 15.

Abstract: Prader-Willi syndrome (PWS) is a complex multiple anomaly syndrome that has been shown to result from deficient expression of paternal chromosome 15(q11-q13). In most cases, it is caused either by deletion of this region in the paternally inherited chromosome 15 or by maternal uniparental disomy (UPD) of chromosome 15. In order to determine whether there are phenotypic differences between patients whose PWS is caused by these two different mechanisms, 54 affected individuals (37 with deletion, 17 with UPD) were personally examined and studied using molecular techniques. The previously recognized increased maternal age in patients with UPD and increased frequency of hypopigmentation in those with deletion were confirmed. Although the frequency and severity of most other manifestations of PWS did not differ significantly between the two groups, those with UPD were less likely to have a "typical" facial appearance. In addition, this group was less likely to show some of the minor manifestations such as skin picking, skill with jigsaw puzzles, and high pain threshold. Females and those with UPD were also older, on average. Possible mechanisms by which these differences could occur and the implications of these differences for diagnosis are described.

High-Activity Catechol-O-Methyltransferase Allele is More Prevalent in Polysubstance Abusers

Abstract: Allelic variants at the catechol-O-methyltransferase (COMT) locus are candidates to contribute to genetic components of interindividual differences in vulnerability to substance abuse. COMT plays a prominent role in dopaminergic circuits important for drug reward, and COMT alleles encode enzymes whose activities vary from three- to four-fold. We compared COMT allele frequencies in control research volunteers reporting insignificant lifetime use of addictive substances with those in volunteers reporting substantial polysubstance use. Homozygosity for the high-activity COMT allele was found in 18% of controls, 31% of volunteers with high lifetime substance use, and 39% meeting DSMIII-R substance abuse criteria [odds ratio (relative risks) 2.0 (control vs. use; 95% confidence interval 1.2-3.5; P < 0.013) and 2.8 (control vs. DSM; 1.3-6.1; P < 0.008)]. Individuals with the high-activity COMT variant may have greater genetic vulnerability to drug abuse.

Initial genomic scan of the NIMH genetics initiative bipolar pedigrees: Chromosomes 3, 5, 15, 16, 17, and 22

Abstract: As part of the four-center NIMH Genetics Initiative on Bipolar Disorder we carried out a genomic scan of chromosomes 3, 5, 15, 16, 17, and 22. Genotyping was performed on a set of 540 DNAs from 97 families, enriched for affected relative pairs and parents where available. We report here the results of the initial 74 markers that have been typed on this set of DNAs. The average distance between markers (u) was 12.3 cM. Nonparametric analysis of excess allele sharing among affected sibling pairs used the SIBPAL program of the S.A.G.E. pack

D2 dopamine receptor polymorphism and brain regional glucose metabolism

Abstract: Positron emission tomography (PET) studies have shown decreased glucose metabolism in brain regions of detoxified alcoholics and cocaine abusers. However, it is not clear whether this decrease is due to chronic drug abuse or a pre-existing condition. Molecular genetic studies have found an association of the D2 dopamine receptor (DRD2) A1 allele with alcoholism and drug abuse. Moreover, reduced central dopaminergic function has been suggested in subjects who carry the A1 allele (A1+) compared with those who do not (A1-). In the present study, using 18F-deoxyglucose, regional glucose metabolism was determined in healthy nonalcohol/nondrug-abusing subjects with the A1+ or A1- allele. The mean relative glucose metabolic rate (GMR) was significantly lower in the A1+ than the A1- group in many brain regions, including the putamen, nucleus accumbens, frontal and temporal gyri and medial prefrontal, occipito-temporal and orbital cortices. Decreased relative GMR in the A1+ group was also found in Broca's area, anterior insula, hippocampus, and substantia nigra. A few brain areas, however, showed increased relative GMR in the A1+ group. Since polymorphism of the DRD2 gene is commonly observed in humans, the importance of differentiating A1+ and A1- alleles subjects in PET studies is suggested.

Multiple malformation syndrome following fluconazole use in pregnancy: Report of an additional patient

Abstract: We report on a patient with malformations following long-term and high-dose maternal fluconazole use during pregnancy. The patient had exorbitism, a large pear-shaped nose, “dysplastic” ears, and radiohumeral synostosis. He is similar to three previously reported patients with in utero exposure to fluconazole and also shares some characteristics with the Antley-Bixler syndrome. The four fluconazole-exposed and malformed infants are compared with one another and with the Antley-Bixler syndrome. We conclude that fluconazole is a teratogen and results in a specific pattern of malformations following first trimester use. Am. J. Med. Genet. 72:253–256, 1997. © 1997 Wiley-Liss, Inc.

Clinical effects of cholesterol supplementation in six patients with the Smith-Lemli-Opitz syndrome (SLOS)

Abstract: We describe the clinical effects of cholesterol supplementation in 6 children with the RSH-"Smith-Lemli-Opitz" syndrome (SLOS). The children ranged in age from birth to 11 years at the onset of therapy, with pretreatment cholesterol levels ranging from 8 to 62 mg/dl. Clinical benefits of therapy were seen in all patients, irrespective of age at onset of treatment, or severity of cholesterol defect. Effects of treatment included improved growth, more rapid developmental progress, and a lessening of problem behaviors. Pubertal progression in older patients, a better tolerance of infection, improvement of gastrointestinal symptoms, and a diminution in photosensitivity and skin rashes were also noted. There were no adverse reactions to treatment with cholesterol. This preliminary study suggests that cholesterol supplementation may be of benefit to patients with the SLOS.

5-HT2C (HTR2C) serotonin receptor gene polymorphism associated with the human personality trait of reward dependence : Interaction with dopamine D4 receptor (D4DR) and dopamine D3 receptor (D3DR) polymorphisms

Abstract: We recently reported an association between the long repeat allele of the dopamine D4 exon III receptor polymorphism and a human personality dimension, novelty seeking, as measured by the tridimensional personality questionnaire (TPQ), a personality instrument designed by Cloninger to reflect heritable facets of human temperament. The D4 receptor polymorphism (D4DR) accounts for only a small percent of the variance for this trait, suggesting that additional genes influence both novelty seeking as well as the other temperaments that are inventoried by the Cloninger TPQ. In the current investigation, we examined, in the original cohort of 120 normal volunteers, two additional coding region polymorphisms, a glycine to serine substitution in the dopamine D3 receptor (D3DR) and a cysteine to serine substitution in the 5-HT2C serotonin receptor (HTR2C). Three-way analysis of variance (TPQ score grouped by D4DR, D3DR and 5-HT2C) demonstrated that reward dependence and persistence scores were significantly reduced by the presence of the less common 5-HT2Cser polymorphism. The effect of the serine substitution in this X-linked serotonin receptor polymorphism on reward dependence was also observed when male and female subject groups were separately analyzed. There was also a significant interaction between the two dopamine receptor polymorphisms and the serotonin polymorphism on reward dependence. In particular, the effect of the 5-HT2C polymorphism on reward dependence was markedly accentuated in individuals who had the long version of the D4DR exon III repeat polymorphism. When present in the same individual, the 5-HT2C and dopamine receptor polymorphisms account for 30% of the observed variance for persistence (RD2) and 13% of the variance for reward dependence scores (RD134). However, the number of subjects with both less common D4DR and 5-HT2C polymorphisms is small, underscoring the importance of verifying this interaction in a larger cohort. Am. J. Med. Genet. 74:65–72, 1997. © 1997 Wiley-Liss, Inc.

Abnormalities of the heart and great arteries in first trimester chromosomally abnormal fetuses

Abstract: Pathological examination of the heart and great arteries was performed in 112 chromosomally abnormal fetuses after surgical termination of pregnancy at 11-16 weeks of gestation. The chromosomal abnormalities were diagnosed by chorion villus sampling which was carried out because screening of the pregnancies by a combination of maternal age and fetal nuchal translucency thickness at 10-14 weeks of gestation identified them as being at increased risk. The group consisted of 60 fetuses with trisomy 21, 29 with trisomy 18, 17 with trisomy 13 and 6 with Ullrich-Turner syndrome. The most common cardiac lesion seen in trisomy 21 fetuses was an atrioventricular or ventricular septal defect. Trisomy 18 was associated with ventricular septal defects and/or polyvalvular abnormalities. In trisomy 13, there were atrioventricular or ventricular septal defects, valvular abnormalities, and either narrowing of the isthmus or truncus arteriosus. Ullrich-Turner syndrome was associated with severe narrowing of the whole aortic arch. In all four groups of chromosomally abnormal fetuses, the aortic isthmus was significantly narrower than in normal fetuses and the degree of narrowing was significantly greater in fetuses with high nuchal translucency thickness. It is postulated that narrowing of the aortic isthmus may be the basis of increased nuchal translucency thickness in all four chromosomal abnormalities.

Elevated rates of severe neural tube defects in a high-prevalence area in Northern China

Abstract: In the northern provinces of China, the birth prevalence rate of neural tube defects (NTDs) is among the highest in the world-at about 6 per 1,000 births in rural areas. A unique population-based birth defects surveillance system in which photographs are taken of infants with selected external birth defects was implemented in two provinces in northern China and two provinces in southern China where NTD rates approximate those in the United States. In the period from March 1992 through December 1993, 660 infants with NTDs were identified by the surveillance project from a birth cohort of 251,567. We compared data from the two surveillance areas in China with data from a low-prevalence area in the United States to determine if the pattern of NTD types differs. Based on birth prevalence rates of NTDs from the Metropolitan Atlanta Congenital Defects Program, the observed to expected ratios for two types of NTDs are markedly increased at 80.8 for craniorachischisis and 25.0 for iniencephaly. Rates of these two NTDs in the southern provinces are increased to a lesser degree with observed to expected ratios of 7.1 for craniorachischisis and 2.7 for iniencephaly. The pattern of NTDs in northern China shows an increase in types that are rare in low-prevalence areas such as metropolitan Atlanta. Increased awareness of varying patterns of NTDs in different populations may have important implications for identifying etiologic and pathogenetic mechanisms of NTDs.

Application of transmission disequilibrium tests to nonsyndromic oral clefts: including candidate genes and environmental exposures in the models.

Abstract: Extensive epidemiological and genetic studies of the cause of oral clefts have demonstrated strong familial aggregation but have failed to yield definitive evidence of any single genetic mechanism. We used the transmission/disequilibrium test (TDT) to investigate the relationship between oral clefts and markers associated with five candidate genes by utilizing 160 parent-offspring trios. Conditional logistic regression models extended the TDT to include covariates as effect modifiers, thus permitting tests for gene-environment interactions. For four of these candidates [transforming growth factor alpha (TGFA), transforming growth factor beta 3 (TGFB3), retinoic acid receptor (RARA), and the proto-oncogene BCL3], we detected modestly elevated odds ratios for the transmission of one marker allele to cleft probands when all the trios were analyzed together. These odds ratios increased when information on type of cleft, race, family history, or maternal smoking were incorporated as effect modifiers. We detected significant interaction between maternal smoking and the transmission of alleles for markers near TGFA and TGFB3; excess transmission of allele 3 at BCL3 was most significant among cleft lip probands; and the odds ratios for transmission of alleles at D19S178 and THRA1 were significant when ethnic group was included in the model. We suggest that utilizing an analytical strategy that allows for stratification of data and incorporating environmental effects into a single analysis may be more effective for detecting genes of small effect.

Methylenetetrahydrofolate reductase variant and schizophrenia/depression

Abstract: Patients with methylenetetrahydrofolate reductase (MTHFR) deficiency often show psychiatric manifestations. Since a common variant of the MTHFR gene, T677(Ala), responsible for the thermolabile MTHFR with less than 50% specific MTHFR activity, has been reported, we examined whether the T677 allele is associated with psychiatric disorders in an unrelated Japanese population consisting of 297 schizophrenics, 32 patients with major depression, 40 patients with bipolar disorder, and 419 controls. The genotype homozygous for the T677 allele was significantly frequently observed in schizophrenics with an odds ratio of 1.9 (P = 0.0006), and in patients with major depression with an odds ratio of 2.8 (P = 0.005). Our data suggest associations of the MTHFR gene variant with schizophrenia and depression in the Japanese.

Genetic testing for breast cancer susceptibility: Awareness and interest among women in the general population

Abstract: Previous research has suggested that demand for genetic testing for breast cancer susceptibility may be quite high, even among those at relatively low risk of carrying a mutation. This study examined the extent to which a group of female HMO enrollees were aware of the discovery of the BRCA1 gene and, without having received detailed information about the test, whether they would be interested in being tested to find out if they have the gene. Factors associated with awareness of and interest in testing were also examined. Four hundred seventy-three women age 50 and over, almost all of whom did not have an increased risk of breast cancer based on family history, were surveyed by telephone. Fifty-one percent of respondents had heard about the discovery of a breast cancer gene. In logistic regression analysis, women who described themselves as comfortable financially, had at least some college education, and were premenopausal were more likely to have heard of the gene discovery than women who were not comfortable financially, had no more than a high school education, and were postmenopausal. Sixty-nine percent of the respondents said that they would be interested in being tested to find out if they had a breast cancer gene. Women who were younger than 60, white, believed their family would benefit if they had a mammogram, and believed that regular mammograms give them a feeling of control over their health, were more likely to be interested in testing than those who were 60 or older, African-American or other, and did not believe that their family would benefit if they had a mammogram or that mammograms give them a feeling of control over their health. These findings have implications for education and counseling. Women who express an interest in being tested must be made fully aware of the limitations and possible consequences of testing. Special efforts may be needed to make information about testing available to women who have low levels of education.

Association between dopamine D4 receptor (D4DR) exon III polymorphism and novelty seeking in Japanese subjects

Abstract: This study was designed to assess the association between novelty seeking and D4DR gene polymorphism in the Japanese population. The 48 bp repeat polymorphism in the third exon of the dopamine D4 receptor gene of 153 normal female students was correlated with personality feature results from the Japanese version of Cloninger's Temperament and Character Inventory. The Novelty Seeking subscale of Exploratory Excitability had a significant association with long alleles of the polymorphic exon III repeat sequence of D4DR. Our results suggest that there is an association between long alleles of the polymorphic exon III repeat sequence of D4DR and the personality traits of the Novelty Seeking subscale of Exploratory Excitability, regardless of racial differences in the frequencies of D4DR exon III repeat polymorphism.

Diagnosis of CMT1A duplications and HNPP deletions by interphase FISH: implications for testing in the cytogenetics laboratory.

Abstract: Charcot-Marie-Tooth (CMT) disease type 1A is an inherited peripheral neuropathy characterized by slowly progressive distal muscle wasting and weakness, decreased nerve conduction velocities, and genetic linkage to 17p12. Most (>98%) CMT1A cases are caused by a DNA duplication of a 1.5-Mb region in 17p12 containing the PMP22 gene. The reciprocal product of the CMT1A duplication is a 1.5-Mb deletion which causes hereditary neuropathy with liability to pressure palsies (HNPP). The most informative current diagnostic testing requires pulsed-field gel electrophoresis to detect DNA rearrangement-specific junction fragments. We investigated the use of interphase FISH for the detection of duplications and deletions for these disorders in the clinical molecular cytogenetics laboratory. Established cell lines or blood specimens from 23 individuals with known molecular diagnoses and 10 controls were obtained and scored using a two-color FISH assay. At least 70% of CMT1A cells displayed three signals consistent with duplications. Using this minimum expected percentile to make a CMT1A duplication diagnosis, all patients with CMT1A showed a range of 71–92% of cells displaying at least three signals. Of the HNPP cases, 88% of cells displayed only one hybridization signal, consistent with deletions. The PMP22 locus from normal control individuals displayed a duplication pattern in ∼9% of cells, interpreted as replication of this locus. The percentage of cells showing replication was significantly lower than in those cells displaying true duplications. We conclude that FISH can be reliably used to diagnose CMT1A and HNPP in the clinical cytogenetics laboratory and to readily distinguish the DNA rearrangements associated with these disorders from individuals without duplication or deletion of the PMP22 locus. Am. J. Med. Genet. 69:325–331, 1997. © 1997 Wiley-Liss, Inc.

Genetic disorders among Palestinian Arabs: 1. Effects of consanguinity.

Abstract: Among Palestinian Arabs the rate of consanguinity is very high and some 44.3% of the marriages are between relatives (22.6% of them between first cousins). In almost 2,000 files from Palestinian Arab families who attended the genetics clinic in the Hadassah Medical Center; we were able to study the effects of consanguinity on different disorders. The consanguinity rate in families with dominant or X-linked disorders and chromosome aberrations was similar to the one observed in the general population. We did not find any significant differences in the rate of consanguineous marriages between the parents and grandparents of children affected with trisomy 21 and the general population. Thus, we were not able to confirm the suggestion that there is an increase risk for trisomies in children/grandchildren of consanguineous parents. Among the parents of patients with rare autosomal recessive disorders the consanguinity rate was much higher than the one of the general population (92.5%). Among the autosomal recessive disorders, which were relatively frequent in the population, there were fewer marriages between relatives; but in most cases the difference from rare disorders is relatively small. The importance of genetic factors in various congenital malformations, such as neural tube defects and cleft lip/palate or in various forms of infertility, was confirmed by the observation of a significantly higher consanguinity rate in the parents of these patients than is observed in the general population.

Macrocephaly‐Cutis marmorata telangiectatica congenita: A distinct disorder with developmental delay and connective tissue abnormalities

Abstract: We describe 13 unrelated children with abnormalities of somatic growth, face, brain, and connective tissue including vasculature. Although the condition in these children falls under the general group of disorders known as cutis marmorata telangiectatica congenita (CMTC), the constellation of abnormalities appears to constitute a distinct and easily recognizable phenotype within this general group. In contrast to most children reported with CMTC, children in this subgroup have a high risk for neurologic abnormalities, including developmental delay, mental retardation, megalencephaly, and hydrocephalus. Early recognition of this condition is important for appropriate surveillance for known complications and parental counseling.

Birth prevalence, mutation rate, sex ratio, parents' age, and ethnicity in Apert syndrome

Abstract: Apert syndrome was studied to determine birth prevalence, mutation rate, sex ratio, parents' age, and ethnicity among 2,493,331 live births registered in the California Birth Defects Monitoring Program (CBDMP) from 1983 through 1993; 31 affected infants were identified. The sample was completed with an additional 22 cases from the Center for Craniofacial Anomalies (CCA), University of California, San Francisco, for a total of 53 affected children. Birth prevalence, calculated from the CBDMP subsample, was 12.4 cases per million live births (confidence interval [CI] 8.6,17.9). The calculated mutation rate was 6.2 × 10−6 per gene per generation. Asians had the highest prevalence (22.3 per million live births; CI 7.1,61.3) and Hispanics the lowest (7.6 per million, CI 3.3-16.4). In the large population-based CBDMP subsample, there was an almost equal number of affected males and females, (sex ratio 0.94) but in the clinical CCA subsample, there were more affected females (sex ratio 0.79). For all cases, the mean age of mothers was 28.9±6.0 years, and of fathers was 34.1±6.2 years. Almost half of fathers were older than 35 years when the child was born; for more than 20% of cases, both parents were older than 35 years. These findings may support the view that point mutations appear to be more commonly associated with paternal than with maternal alleles. Representing the largest systematically ascertained population-based study of Apert syndrome to date, they provide a reliable basis for genetic counseling and decision-making, and for focused research to define the cause of this syndrome. Am. J. Med. Genet. 72:394–398, 1997. © 1997 Wiley-Liss, Inc.

Schizophrenia in the genetic isolate of Finland.

Abstract: We compared the features of schizophrenia in the homogeneous population of Finland (population about 5,000,000) and in an internal isolate in northeastern Finland inhabited in the 1680s by a small group of founders (current population about 18,000) in a register-based epidemiological study. We identified all cases with a diagnosis of schizophrenia in Finland born between 1940-1969 using three national computerized registers and found a total of 267 schizophrenia patients in the internal isolate and 29,124 in Finland. The lifetime prevalence was 2.21% in the internal isolate and 1.21% in Finland, respectively. The age-corrected lifetime risk was 3.2% in the internal isolate and 1.1% in the whole country. The risk of schizophrenia to siblings in the internal isolate was 6.4% (95% confidence interval 0.052, 0.078), 9.1% (95% CI 0.062, 0.130), and 6.8% (95% CI 0.028, 0.135) given 1, 2, or 3 affected siblings, and for all Finland 4.2% (95% CI 0.036, 0.043), 6.4% (95% CI 0.058, 0.071), and 8.7% (95% CI 0.068, 0.107) given 1, 2, or 3, affected siblings, respectively. The mean number of children in schizophrenia families and thus the number of families having at least two affected individuals were clearly higher in the isolate (24.9% vs 9.2%). We did not find any other epidemiological features differing between these two regions. It seems that the family material collected from the internal isolate is a representative subsample from the entire country and hopefully it enables easier identification of at least some predisposing genes for schizophrenia due to its unique population structure.

European collaborative research on mosaicism in CVS (EUCROMIC)--fetal and extrafetal cell lineages in 192 gestations with CVS mosaicism involving single autosomal trisomy.

Abstract: Cytogenetic information on cells from cytotrophoblast, villus mesenchyme, and one or more fetal tissues was available for 192 gestations with mosaicism or non-mosaic fetoplacental discrepancy involving a single autosomal trisomy in the chorionic villus sample (CVS), registered in a collaborative study (EUCROMIC) during the period 1986–1994. In order to identify predictors of confined placental mosaicism (CPM), generalized mosaicism and/or uniparental disomy (UPD), distribution of the mosaic and non-mosaic aneuploid cell lines in the different fetal and extrafetal cell lineages were analyzed. Data were related to existing hypotheses on mechanisms leading to fetoplacental discrepancies and early extraembryonic cell differentiation. Trisomy 21 mosaicism was the one most frequently confirmed in the fetus. Non-mosaic trisomy 13, 18, and 21 in the villus mesenchyme indicated the presence of a trisomic cell line in the fetus proper. Non-mosaic trisomy 2, 7, and 16 in villus mesenchyme was always found with concomitant mosaic or non-mosaic trisomy in the cytotrophoblast, but was never recovered in the fetus. Mosaic trisomy 3, 7, and 20 was predominantly restricted to the cytotrophoblast, mosaic trisomy 2 to the villus mesenchyme. Trisomies 15 and 16 were most often found in both cytotrophoblast and villus mesenchyme and not in fetal cells. This supports the hypothesis that mosaicism/discrepancy for trisomies 15 and 16 results more often than for the other trisomies from trisomic zygote rescue, enhancing their risk for UPD. We recommend, due to the risk of fetal trisomy, amniocentesis in all gestations involving mosaic autosomal trisomy in villus mesenchyme. In gestations with mosaic or non-mosaic autosomal trisomy in both cytotrophoblast and villus mesenchyme we recommend, in order to exclude fetal trisomy and/or UPD, depending on the chromosome involved, further examination by amniocentesis, ultrasound and/or test for UPD. We also recommend, due to a small but not negligible risk of false negative and false positive diagnoses, not to solely use direct preparation. Am. J. Med. Genet. 70:179–187, 1997. © 1997 Wiley-Liss, Inc.

Developmental tasks of childhood and adolescence: Implications for genetic testing

Abstract: Many reports have recently recommended a careful weighing of the potential benefits and harms of genetic testing (carrier or predisposition) of children and adolescents [Andrews et al., Washington DC: National Academy Press, 1994; Wertz et al., JAMA, 272:875-881, 1994; Clinical Genetics Society (UK), J Med Genet, 31:785-797, 1994; ASHJ/ACMG, Am J Hum Genet, 57:1233-1241, 1995]. Despite this, youngsters are currently being tested for late-onset disorders as well as for carrier status [Reilly and Wertz, Am J Hum Genet, 57:A57, 1995]. Many children to be tested will be those in at-risk families, who may already have experienced the chronic illness or death of a close relative. Thus, reactions to testing will be influenced by prior family experiences. Emotional reactions to testing will be determined by both the child's cognitive and psychosocial development. Testing of adolescents may alter the achievement of developmental tasks, including seeking freedom from parental figures, establishment of personal identity, handling of sexual energies, and remodeling of former idealizations of self and others. There are many potential dilemmas in deciding whether to test a child or adolescent for genetic status. If parents choose not to test, the risk is for later difficulty integrating such information into the self concept. If parents test and do not tell results, the risk is for creating a climate of family secrecy. If parents test and tell results, the risk is robbing the child of the autonomy of his or her own later decision. Perhaps the question of whether to test is not the real question. More than genetic testing, genetic counseling is of crucial importance in thoughtful decisions concerning whether to test an individual child or adolescent. A more important question may be how to provide unaffected children in at-risk families with appropriate counseling. Provision of psychosocial support to at-risk families will enable the child to encounter genetic testing, if necessary, supported with the best possible resources.

Epidemiology of holoprosencephaly and phenotypic characteristics of affected children: New York State, 1984-1989

Abstract: Holoprosencephaly is a congenital defect of the median structures of the brain and face The epidemiology is poorly known due to the paucity of population-based studies This study describes the epidemiology of holoprosencephaly in a large population, using cases identified through the New York State Congenital Malformations Registry, and born in 1984-1989 We describe the craniofacial abnormalities present, their frequency, and their cooccurrence, and we examine the correspondence between the severity of craniofacial abnormalities, chromosomal abnormalities, and severity of the brain defect Liveborn cases totaled 78, yielding a prevalence of 48 per 100,000 live births Prevalence among girls was nearly double that in boys, and was 42 times higher among infants of mothers under age 18 compared to infants of older mothers Only 98% of all cases had no craniofacial abnormalities other than the brain defect Eye malformations were present in 768%, nose malformations in 695%, ear malformations in 50%, and oral clefts in 415% These malformations arise at different times during gestation The variability in patterns of cooccurrence suggests variability in the developmental pathways and/or timing of developmental derangements which result in holoprosencephaly This, in turn, is consistent with a model of multiple causes Children with alobar holoprosencephaly tended to have the most severe craniofacial anomalies, but the correspondence was not 100% Craniofacial phenotype does not consistently discriminate between cytogenetically normal and abnormal cases