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Showing papers by "Boston Children's Hospital published in 1998"


Journal ArticleDOI
TL;DR: Given the limitations of the data on which they are based, this report provides the best available prevalence estimates for arthritis and other rheumatic conditions overall, and for selected musculoskeletal disorders, in the US population.
Abstract: Objective To provide a single source for the best available estimates of the national prevalence of arthritis in general and of selected musculoskeletal disorders (osteoarthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, the spondylarthropathies, systemic lupus erythematosus, scleroderma, polymyalgia rheumatica/giant cell arteritis, gout, fibromyalgia, and low back pain). Methods The National Arthritis Data Workgroup reviewed data from available surveys, such as the National Health and Nutrition Examination Survey series. For overall national estimates, we used surveys based on representative samples. Because data based on national population samples are unavailable for most specific musculoskeletal conditions, we derived data from various smaller survey samples from defined populations. Prevalence estimates from these surveys were linked to 1990 US Bureau of the Census population data to calculate national estimates. We also estimated the expected frequency of arthritis in the year 2020. Results Current national estimates are provided, with important caveats regarding their interpretation, for self-reported arthritis and selected conditions. An estimated 15% (40 million) of Americans had some form or arthritis in 1995. By the year 2020, an estimated 18.2% (59.4 million) will be affected. Conclusion Given the limitations of the data on which they are based, this report provides the best available prevalence estimates for arthritis and other rheumatic conditions overall, and for selected musculoskeletal disorders, in the US population.

2,667 citations


Journal ArticleDOI
17 Apr 1998-Cell
TL;DR: It is shown that cardiac hypertrophy is induced by the calcium-dependent phosphatase calcineurin, which dephosphorylates the transcription factor NF-AT3, enabling it to translocate to the nucleus.

2,596 citations


Journal ArticleDOI
02 Oct 1998-Cell
TL;DR: It is suggested that mutant huntingtin acts within the nucleus to induce neurodegeneration, however, intranuclear inclusions may reflect a cellular mechanism to protect against huntingtin-induced cell death.

1,646 citations


Journal ArticleDOI
TL;DR: This work proposes a revision of the classification of the Ehlers-Danlos syndromes based primarily on the cause of each type based on major and minor diagnostic criteria defined for each type and complemented whenever possible with laboratory findings.
Abstract: Categorization of the Ehlers-Danlos syndromes began in the late 1960s and was formalized in the Berlin nosology. Over time, it became apparent that the diagnostic criteria established and published in 1988 did not discriminate adequately between the different types of Ehlers-Danlos syndromes or between Ehlers-Danlos syndromes and other phenotypically related conditions. In addition, elucidation of the molecular basis of several Ehlers-Danlos syndromes has added a new dimension to the characterization of this group of disorders. We propose a revision of the classification of the Ehlers-Danlos syndromes based primarily on the cause of each type. Major and minor diagnostic criteria have been defined for each type and complemented whenever possible with laboratory findings. This simplified classification will facilitate an accurate diagnosis of the Ehlers-Danlos syndromes and contribute to the delineation of phenotypically related disorders.

1,600 citations


Journal ArticleDOI
TL;DR: Increased application of advanced molecular technologies in clinical laboratories has significantly improved the capacity to diagnose STEC infection early in the course of disease and to detect low levels of environmental contamination, creating a potential window of opportunity for future therapeutic intervention.
Abstract: Since their initial recognition 20 years ago, Shiga toxin-producing Escherichia coli (STEC) strains have emerged as an important cause of serious human gastrointestinal disease, which may result in life-threatening complications such as hemolytic-uremic syndrome. Food-borne outbreaks of STEC disease appear to be increasing and, when mass-produced and mass-distributed foods are concerned, can involve large numbers of people. Development of therapeutic and preventative strategies to combat STEC disease requires a thorough understanding of the mechanisms by which STEC organisms colonize the human intestinal tract and cause local and systemic pathological changes. While our knowledge remains incomplete, recent studies have improved our understanding of these processes, particularly the complex interaction between Shiga toxins and host cells, which is central to the pathogenesis of STEC disease. In addition, several putative accessory virulence factors have been identified and partly characterized. The capacity to limit the scale and severity of STEC disease is also dependent upon rapid and sensitive diagnostic procedures for analysis of human samples and suspect vehicles. The increased application of advanced molecular technologies in clinical laboratories has significantly improved our capacity to diagnose STEC infection early in the course of disease and to detect low levels of environmental contamination. This, in turn, has created a potential window of opportunity for future therapeutic intervention.

1,512 citations


Journal ArticleDOI
01 Apr 1998-Neuron
TL;DR: The findings suggest that a CREB family member acts cooperatively with an additional transcription factor(s) to regulate BDNF transcription, and concludes that the BDNF gene is aCREB family target whose protein product functions at synapses to control adaptive neuronal responses.

1,492 citations


Journal ArticleDOI
TL;DR: The importance of a plant-based diet is evident from the current dietary recommendations that emphasize an increase in the proportion and amount of fruit and vegetables that should be consumed, and interpretation of the role of individual components of the diet is difficult from epidemiologic and dietary studies.

1,129 citations


Journal ArticleDOI
TL;DR: Two multiplex PCR assays for the detection and genetic characterization of STEC in cultures of feces or foodstuffs detected STEC of the appropriate genotype in primary fecal cultures from five patients with hemolytic-uremic syndrome and three with bloody diarrhea.
Abstract: Shiga toxigenic Escherichia coli (STEC) comprises a diverse group of organisms capable of causing severe gastrointestinal disease in humans. Within the STEC family, certain strains appear to be of greater virulence for humans, for example, those belonging to serogroups O111 and O157 and those with particular combinations of other putative virulence traits. We have developed two multiplex PCR assays for the detection and genetic characterization of STEC in cultures of feces or foodstuffs. Assay 1 utilizes four PCR primer pairs and detects the presence of stx1, stx2 (including variants of stx2), eaeA, and enterohemorrhagic E. coli hlyA, generating amplification products of 180, 255, 384, and 534 bp, respectively. Assay 2 uses two primer pairs specific for portions of the rfb (O-antigen-encoding) regions of E. coli serotypes O157 and O111, generating PCR products of 259 and 406 bp, respectively. The two assays were validated by testing 52 previously characterized STEC strains and observing 100% agreement with previous results. Moreover, assay 2 did not give a false-positive O157 reaction with enteropathogenic E. coli strains belonging to clonally related serogroup O55. Assays 1 and 2 detected STEC of the appropriate genotype in primary fecal cultures from five patients with hemolytic-uremic syndrome and three with bloody diarrhea. Thirty-one other primary fecal cultures from patients without evidence of STEC infection were negative.

1,102 citations


Journal ArticleDOI
TL;DR: This minimally invasive technique, which requires neither cartilage incision nor resection for correction of pectus excavatum, is effective and has had excellent long-term results.

1,091 citations


Journal ArticleDOI
TL;DR: It is shown that co-expression of the mutant ß1 subunit with a brain Na+-channel ß subunit in Xenopus laevis oocytes demonstrates that the mutation interferes with the ability of the subunit to modulate channel-gating kinetics consistent with a loss-of-function allele, developing the theme that idiopathic epilepsies are a family of channelopathies.
Abstract: Febrile seizures affect approximately 3% of all children under six years of age and are by far the most common seizure disorder. A small proportion of children with febrile seizures later develop ongoing epilepsy with afebrile seizures. Segregation analysis suggests the majority of cases have complex inheritance but rare families show apparent autosomal dominant inheritance. Two putative loci have been mapped (FEB1 and FEB2), but specific genes have not yet been identified. We recently described a clinical subset, termed generalized epilepsy with febrile seizures plus (GEFS+), in which many family members have seizures with fever that may persist beyond six years of age or be associated with afebrile generalized seizures. We now report linkage, in another large GEFS+ family, to chromosome region 19q13.1 and identification of a mutation in the voltage-gated sodium (Na+)-channel beta1 subunit gene (SCN1B). The mutation changes a conserved cysteine residue disrupting a putative disulfide bridge which normally maintains an extracellular immunoglobulin-like fold. Co-expression of the mutant beta1 subunit with a brain Na+-channel alpha subunit in Xenopus laevis oocytes demonstrates that the mutation interferes with the ability of the subunit to modulate channel-gating kinetics consistent with a loss-of-function allele. This observation develops the theme that idiopathic epilepsies are a family of channelopathies and raises the possibility of involvement of other Na+-channel subunit genes in febrile seizures and generalized epilepsies with complex inheritance patterns.

1,015 citations


Journal ArticleDOI
09 Jan 1998-Cell
TL;DR: A novel 10 kb brain-specific cDNA interrupted by a balanced translocation in an XLIS patient that encodes a novel 40 kDa predicted protein named Doublecortin, which may define an Abl-dependent pathway regulating neuronal migration.

Journal ArticleDOI
TL;DR: The presence of depression in parents should alert clinicians to the fact that their children also may be depressed and therefore in need of services.
Abstract: Objective To review the literature investigating the effects of parental affective illness on children over the past decade. Method A computerized search of articles published over the past 10 years was completed. Articles were reviewed and relevant studies are presented. Results Over the course of the past 10 years a number of longitudinal studies have confirmed that children of affectively ill parents are at a greater risk for psychiatric disorders than children from homes with non-ill parents. Life table estimates indicate that by the age of 20 a child with an affectively ill parent has a 40° chance of experiencing an episode of major depression. Children from homes with affectively ill parents are more likely to exhibit general difficulties in functioning, increased guilt, and interpersonal difficulties as well as problems with attachment. Marital difficulties, parenting problems, and chronicity and severity of parental affective illness have been associated with the increased rates of disorder observed in these children. Conclusion The presence of depression in parents should alert clinicians to the fact that their children also may be depressed and therefore in need of services.

Journal ArticleDOI
TL;DR: The hypothesis that Nramp2 is the protein defective in the Belgrade rat is confirmed and the possibility that the phenotype shared by mk and b animals is unique to the G185R mutation raised, as the phenotypic characteristics of these animals indicate that NRamp2 are essential both for normal intestinal iron absorption and for transport of iron out of the transferrin cycle endosome.
Abstract: The Belgrade (b) rat has an autosomal recessively inherited, microcytic, hypochromic anemia associated with abnormal reticulocyte iron uptake and gastrointestinal iron absorption. The b reticulocyte defect appears to be failure of iron transport out of endosomes within the transferrin cycle. Aspects of this phenotype are similar to those reported for the microcytic anemia (mk) mutation in the mouse. Recently, mk has been attributed to a missense mutation in the gene encoding the putative iron transporter protein Nramp2. To investigate the possibility that Nramp2 was also mutated in the b rat, we established linkage of the phenotype to the centromeric portion of rat chromosome 7. This region exhibits synteny to the chromosomal location of Nramp2 in the mouse. A polymorphism within the rat Nramp2 gene cosegregated with the b phenotype. A glycine-to-arginine missense mutation (G185R) was present in the b Nramp2 gene, but not in the normal allele. Strikingly, this amino acid alteration is the same as that seen in the mk mouse. Functional studies of the protein encoded by the b allele of rat Nramp2 demonstrated that the mutation disrupted iron transport. These results confirm the hypothesis that Nramp2 is the protein defective in the Belgrade rat and raise the possibility that the phenotype shared by mk and b animals is unique to the G185R mutation. Furthermore, the phenotypic characteristics of these animals indicate that Nramp2 is essential both for normal intestinal iron absorption and for transport of iron out of the transferrin cycle endosome.

Journal ArticleDOI
TL;DR: Data provide evidence that SPGP is the human bile salt export pump (BSEP), and the product of the orthologous rat gene has been shown to be an effective bile acid transporter in vitro.
Abstract: The progressive familial intrahepatic cholestases (PFIC) are a group of inherited disorders with severe cholestatic liver disease from early infancy. A subgroup characterized by normal serum cholesterol and gamma-glutamyltranspeptidase (gammaGT) levels is genetically heterogeneous with loci on chromosomes 2q (PFIC2) and 18q. The phenotype of the PFIC2-linked group is consistent with defective bile acid transport at the hepatocyte canalicular membrane. The PFIC2 gene has now been identified by mutations in a positional candidate, BSEP, which encodes a liver-specific ATP-binding cassette (ABC) transporter, sister of p-glycoprotein (SPGP). The product of the orthologous rat gene has been shown to be an effective bile acid transporter in vitro. These data provide evidence that SPGP is the human bile salt export pump (BSEP).

Journal ArticleDOI
TL;DR: In vitro and in vivo observations shed light on the cell–cell interactions that occur during vessel development, as well as in pathologies in which developmental processes are recapitulated.
Abstract: We aimed to determine if and how endothelial cells (EC) recruit precursors of smooth muscle cells and pericytes and induce their differentiation during vessel formation. Multipotent embryonic 10T1/2 cells were used as presumptive mural cell precursors. In an under-agarose coculture, EC induced migration of 10T1/2 cells via platelet-derived growth factor BB. 10T1/2 cells in coculture with EC changed from polygonal to spindle-shaped, reminiscent of smooth muscle cells in culture. Immunohistochemical and Western blot analyses were used to examine the expression of smooth muscle (SM)-specific markers in 10T1/2 cells cultured in the absence and presence of EC. SM-myosin, SM22α, and calponin proteins were undetectable in 10T1/2 cells cultured alone; however, expression of all three SM-specific proteins was significantly induced in 10T1/2 cells cocultured with EC. Treatment of 10T1/2 cells with TGF-β induced phenotypic changes and changes in SM markers similar to those seen in the cocultures. Neutralization of TGF-β in the cocultures blocked expression of the SM markers and the shape change. To assess the ability of 10T1/2 cells to contribute to the developing vessel wall in vivo, prelabeled 10T1/2 cells were grown in a collagen matrix and implanted subcutaneously into mice. The fluorescently marked cells became incorporated into the medial layer of developing vessels where they expressed SM markers. These in vitro and in vivo observations shed light on the cell–cell interactions that occur during vessel development, as well as in pathologies in which developmental processes are recapitulated.

Journal ArticleDOI
TL;DR: The concurrence of primarily shaft and filopodial synapses in the first postnatal week suggests that Filopodia recruit shaft synapses that later give rise to spines through a process of outgrowth.
Abstract: To determine the role of dendritic filopodia in the genesis of excitatory synaptic contacts and dendritic spines in hippocampal area CA1, serial section electron microscopy and three-dimensional analysis of 16 volumes of neuropil from nine male rat pups, aged postnatal day 1 (P1) through P12, were performed. The analysis revealed that numerous dendritic filopodia formed asymmetric synaptic contacts with axons and with filopodia extending from axons, especially during the first postnatal week. At P1, 22 +/- 5.5% of synapses occurred on dendritic filopodia, with 19 +/- 5.9% on filopodia at P4, 20 +/- 8.0% at P6, decreasing to 7.2 +/- 4.7% at P12 (p < 0.02). Synapses were found at the base and along the entire length of filopodia, with many filopodia exhibiting multiple synaptic contacts. In all, 162 completely traceable dendritic filopodia received 255 asymmetric synaptic contacts. These synapses were found at all parts of filopodia with equal frequency, usually occurring on fusiform swellings of the diameter. Most synaptic contacts (53 +/- 11%) occurred directly on dendritic shafts during the first postnatal week. A smaller but still substantial portion (32 +/- 12%) of synapses were on shafts at P12 (p < 0.036). There was a highly significant (p < 0.0002) increase in the proportion of dendritic spine synapses with age, rising from just 4.9 +/- 4.3% at P1 to 37 +/- 14% at P12. The concurrence of primarily shaft and filopodial synapses in the first postnatal week suggests that filopodia recruit shaft synapses that later give rise to spines through a process of outgrowth.

Journal ArticleDOI
TL;DR: Elevated CRP at presentation in patients with unstable angina or NQMI is correlated with increased 14-day mortality, even in Patients with a negative rapid cTnT assay, which provides complementary information for stratifying patients with regard to mortality risk.

Journal ArticleDOI
12 Jun 1998-Cell
TL;DR: Analysis of muscle biopsies from two patients carrying Paraplegin mutations showed typical signs of mitochondrial OXPHOS defects, thus suggesting a mechanism for neurodegeneration in HSP-type disorders.

Journal ArticleDOI
TL;DR: A large body of studies show that both children and their mothers, as groups, are at increased risk for psychosocial adjustment problems compared to peers, but that there is considerable individual variation in outcome.
Abstract: Research conducted primarily over the past 5-8 years on the psychosocial effects of pediatric chronic physical disorders on children and their families is reviewed. A large body of studies show that both children and their mothers, as groups, are at increased risk for psychosocial adjustment problems compared to peers, but that there is considerable individual variation in outcome. Since the last review on this topic (Eiser, 1990a), many studies have been conducted to identify risk and resistance factors associated with differences in adjustment among these children and their mothers. Improvements are noted in the theoretical basis for this work, programmatic nature of some of the research, and efforts at producing clinically relevant information. Evaluations of interventions, however, are lagging. Critical issues and future directions regarding developmental approaches, theory, method, measurement, and intervention are discussed.

Journal ArticleDOI
TL;DR: An important role for Hesx1/HESX1 in forebrain, midline and pituitary development in mouse and human is suggested.
Abstract: During early mouse development the homeobox gene Hesx1 is expressed in prospective forebrain tissue, but later becomes restricted to Rathke's pouch, the primordium of the anterior pituitary gland. Mice lacking Hesx1 exhibit variable anterior CNS defects and pituitary dysplasia. Mutants have a reduced prosencephalon, anopthalmia or micropthalmia, defective olfactory development and bifurcations in Rathke's pouch. Neonates exhibit abnormalities in the corpus callosum, the anterior and hippocampal commissures, and the septum pellucidum. A comparable and equally variable phenotype in humans is septo-optic dysplasia (SOD). We have cloned human HESX1 and screened for mutations in affected individuals. Two siblings with SOD were homozygous for an Arg53Cys missense mutation within the HESX1 homeodomain which destroyed its ability to bind target DNA. These data suggest an important role for Hesx1/HESX1 in forebrain, midline and pituitary development in mouse and human.

Journal ArticleDOI
TL;DR: In this paper, the authors localized the Wolfram syndrome (WFS) gene to a BAC/P1 contig of less than 250 kb and found that mutations in a novel gene encoding a putative transmembrane protein were associated with the disease phenotype.
Abstract: Wolfram syndrome (WFS; OMIM 222300) is an autosomal recessive neurodegenerative disorder defined by young-onset non-immune insulin-dependent diabetes mellitus and progressive optic atrophy. Linkage to markers on chromosome 4p was confirmed in five families. On the basis of meiotic recombinants and disease-associated haplotypes, the WFS gene was localized to a BAC/P1 contig of less than 250 kb. Mutations in a novel gene (WFS1) encoding a putative transmembrane protein were found in all affected individuals in six WFS families, and these mutations were associated with the disease phenotype. WFS1 appears to function in survival of islet s-cells and neurons.

Journal ArticleDOI
TL;DR: The pharmacological inhibition of poly(ADP-ribose) synthetase is a novel approach for the experimental therapy of various forms of inflammation and shock, stroke, myocardial and intestinal ischaemia-reperfusion, and diabetes mellitus.

Journal ArticleDOI
TL;DR: This gene, called FIC1, is the first identified human member of a recently described subfamily of P-type ATPases; ATP-dependent aminophospholipid transport is the previously described function of members of this subfamily.
Abstract: Cholestasis, or impaired bile flow, is an important but poorly understood manifestation of liver disease. Two clinically distinct forms of inherited cholestasis, benign recurrent intrahepatic cholestasis (BRIC) and progressive familial intrahepatic cholestasis type 1 (PFIC1), were previously mapped to 18q21. Haplotype analysis narrowed the candidate region for both diseases to the same interval of less than 1 cM, in which we identified a gene mutated in BRIC and PFIC1 patients. This gene (called FIC1) is the first identified human member of a recently described subfamily of P-type ATPases; ATP-dependent aminophospholipid transport is the previously described function of members of this subfamily. FIC1 is expressed in several epithelial tissues and, surprisingly, more strongly in small intestine than in liver. Its protein product is likely to play an essential role in enterohepatic circulation of bile acids; further characterization of FIC1 will facilitate understanding of normal bile formation and cholestasis.

Journal ArticleDOI
28 May 1998-Nature
TL;DR: The characterization of a regulatory NMDAR subunit, NR3A, is reported, which is expressed primarily during brain development and suggested to be involved in the development of synaptic elements by modulating N MDAR activity.
Abstract: The NMDA (N -methyl-D-aspartate) subclass of glutamate receptor1 is essential for the synaptic plasticity thought to underlie learning and memory2,3,4 and for synaptic refinement during development5,6. It is currently believed that the NMDA receptor (NMDAR) is a heteromultimeric channel comprising the ubiquitous NR1 subunit and at least one regionally localized NR2 subunit7,8,9,10,11. Here we report the characterization of a regulatory NMDAR subunit, NR3A (formerly termed NMDAR-L or χ-1), which is expressed primarily during brain development12,13. NR3Aco-immunoprecipitates with receptor subunits NR1 and NR2 in cerebrocortical extracts. In single-channel recordings from Xenopus oocytes, addition of NR3A to NR1 and NR2 leads to the appearance of a smaller unitary conductance. Genetic knockout of NR3A in mice results in enhanced NMDA responses and increased dendritic spines in early postnatal cerebrocortical neurons. These data suggest that NR3A is involved in the development of synaptic elements by modulating NMDAR activity.

Journal ArticleDOI
TL;DR: Investigation of time trends in the prevalence of asthma and allergic diseases among children living in the eastern part of Germany suggests important differences in the development of atopic disorders.

Journal ArticleDOI
TL;DR: Calcium-activated tissue transglutaminase autoantibody ELISA is highly accurate in detecting untreated celiac disease and seems to be the target self-antigen for endomysial antibodies.

Journal ArticleDOI
TL;DR: The addition of autologous BMT to four courses of intensive chemotherapy substantially reduces the risk of relapse in all risk groups, leading to improvement in long-term survival.

Journal ArticleDOI
15 Oct 1998-Nature
TL;DR: It is shown that presenilin-1 forms a complex with β-catenin in vivo that increases β-Catenin stability, which increases neuronal vulnerability to apoptosis induced by amyloid-β protein.
Abstract: Mutations of the presenilin-1 gene are a major cause of familial early-onset Alzheimer's disease. Presenilin-1 can associate with members of the catenin family of signalling proteins, but the significance of this association is unknown. Here we show that presenilin-1 forms a complex with beta-catenin in vivo that increases beta-catenin stability. Pathogenic mutations in the presenilin-1 gene reduce the ability of presenilin-1 to stabilize beta-catenin, and lead to increased degradation of beta-catenin in the brains of transgenic mice. Moreover, beta-catenin levels are markedly reduced in the brains of Alzheimer's disease patients with presenilin-1 mutations. Loss of beta-catenin signalling increases neuronal vulnerability to apoptosis induced by amyloid-beta protein. Thus, mutations in presenilin-1 may increase neuronal apoptosis by altering the stability of beta-catenin, predisposing individuals to early-onset Alzheimer's disease.

Journal ArticleDOI
TL;DR: An epileptic seizure classification based exclusively on ictal semiology is proposed, and seizures are classified as follows: grand mal, dystonic, and convulsive.
Abstract: We propose an epileptic seizure classification based exclusively on ictal semiology. In this semiological seizure classification (SSC), seizures are classified as follows: a. Auras are ictal manifestations having sensory, psychosensory, and experiential symptoms. b. Autonomic seizures are seizures in which the main ictal manifestations are objectively documented autonomic alterations. c. "Dialeptic" seizures have as their main ictal manifestations an alteration of consciousness that is independent of ictal EEG manifestations. The new term "dialeptic" seizure has been coined to differentiate this concept from absence seizures (dialeptic seizures with a generalized ictal EEG) and complex partial seizures (dialeptic seizures with a focal ictal EEG). d. Motor seizures are characterized mainly by motor symptoms and are subclassified as simple or complex. Simple motor seizures are characterized by simple, unnatural movements that can be elicited by electrical stimulation of the primary and supplementary motor area (myoclonic, tonic, clonic and tonic-clonic, versive). Complex motor seizures are characterized by complex motor movements that resemble natural movements but that occur in an inappropriate setting ("automatisms"). e. Special seizures include seizures characterized by "negative" features (atonic, astatic, hypomotor, akinetic, and aphasic seizures). The SSC identifies in detail the somatotopic distribution of the ictal semiology as well as the seizure evolution. The advantages of a pure SSC, as opposed to the current classification of the International League Against Epilepsy (ILAE), which is actually a classification of electroclinical syndromes, are discussed.

Journal ArticleDOI
TL;DR: A novel gene, CTNS, which mapped to the deletion interval is identified, which encodes an integral membrane protein, cystinosin, with features of a lysosomal membrane protein.
Abstract: Nephropathic cystinosis, an autosomal recessive disorder resulting from defective lysosomal transport of cystine, is the most common inherited cause of renal Fanconi syndrome. The cystinosis gene has been mapped to chromosome 17p13. We found that the locus D17S829 was homozygously deleted in 23 out of 70 patients, and identified a novel gene, CTNS, which mapped to the deletion interval. CTNS encodes an integral membrane protein, cystinosin, with features of a lysosomal membrane protein. Eleven different mutations, all predicted to cause loss of function of the protein, were found to segregate with the disorder.