3613 results for "*geneti*"

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• NEI CIDR Methylation Profiling of Primary Open Angle Glaucoma in GLAUGEN Samples

  This is a case-control study of Primary Open Angle Glaucoma (POAG). POAG is a progressive optic neuropathy that eventually leads to blindness. More than 30 million people worldwide have Primary Open Angle Glaucoma (POAG), of which greater than 3 million are blind. Gene expression changes in the retina have been observed for POAG. Several recent studies, including the GLAUGEN (Glaucoma Gene Environment) initiative have used GWAS to identify correlative regions of the genome. Despite this, the genetic basis of Glaucoma is not well understood. Epigenetic variation may account for low heritability and environmental effects on human disease. Despite the significant advances being made in understanding the role of epigenetics in gene regulation in other fields, little is known about the relationship between DNA methylation patterns, retinal gene expression, and retinal disease. The goal of this study is to identify differentially methylated regions in the peripheral blood of patients with POAG. The case identification is as per the GLAUGEN description: Cases and controls were recruited from ophthalmology clinics and were examined by ophthalmologists. For cases the clinical exam included intraocular pressure measurements, optic nerve assessment and visual field evaluation. Controls had no family history of glaucoma, normal intraocular pressure and normal optic nerves. POAG and control samples come from Massachusetts Eye and Ear Infirmary (MEEI). These samples were collected and genotyped as part of the GLAUGEN study. From the MEEI, 50 patients were selected from POAG pedigrees, to include all the probands genotyped by CIDR and are currently undergoing exome sequencing, and to include additional genotyped probands who belong to pedigrees of sufficient size and structure that parent of origin effects could be evaluated. Additional individual-level phenotype and genotype data may be obtained through the authorized access portal of phs000308 (Geneva - Glaugen GWAS Study).

  Study phs000461

• T2D-GENES Project 2: San Antonio Mexican American Family Studies

  The Type 2 Diabetes (T2D) Genetic Exploration by Next-generation sequencing in Ethnic Samples (T2D-GENES) Consortium is a collaborative international effort to identify genes influencing susceptibility to T2D in multiple ethnic groups using next generation sequencing. T2D-GENES Project 2 is a complex pedigree-based study designed to identify low frequency or rare variants influencing susceptibility to T2D, using whole genome sequence (WGS) information from 1,043 individuals in 20 Mexican American T2D-enriched pedigrees from San Antonio, Texas. The major objectives of this study are to identify low frequency or rare variants in and around known common variant signals for T2D, as well as to find novel low frequency or rare variants influencing susceptibility to T2D. The sampled individuals are obtained from two studies: the San Antonio Family Heart Study (SAFHS) and the San Antonio Family Diabetes/Gallbladder Study (SAFDGS), collectively referred to as the San Antonio Mexican American Family Studies (SAMAFS). The strategy is to sequence approximately 600 individuals at an average of 50x coverage across the entire genome, then impute genome wide genotypes for about 440 additional family members. The 600 sequenced individuals are specifically chosen for their value in imputing sequence information into other family members. By studying large pedigrees, we expect to find multiple individuals carrying each genetic variant, even if this variant is very rare in the population at large. Thus, a pedigree-based approach provides an excellent opportunity for identifying rare novel variants influencing risk of T2D and quantitative variation in T2D-related phenotypes. The whole genome sequencing has been done commercially by Complete Genomics, Inc. (CGI). The final data set includes whole genome sequence data for 607 individuals. After quality control, 585 sequenced individuals provide data for family based imputation, using Merlin linkage analysis software, into approximately 440 additional family members for whom chip based genotypes are available to indicate which parental haplotype is transmitted. Extensive phenotype data is provided for 1048 individuals. These include 5 sequenced individuals who do not belong to any of the 20 large pedigrees. Phenotype information was collected between 1991 and 2011 in the two contributing longitudinal studies. SAFHS participants may have information from up to 5 visits, and SAFDGS participants may have up to 4 visits. The clinical variables reported are coordinated with T2D-GENES Project 1 (multi-ethnic exome sequencing) and include T2D status and age at diagnosis, glycemic traits (fasting and 2 hour glucose and insulin), blood pressure, blood lipids (total cholesterol, HDL cholesterol, calculated LDL cholesterol and triglycerides), clinical chemistry (cystatin c, glutamic acid decarboxylase antibody titer (GadAb), creatinine, adiponectin and leptin). Glycated hemoglobin (HbA1c) was not measured for these individuals and insulin C-peptide is not included in this data set. Additional phenotype data include the medication status at each visit, classified in four categories as any current use of diabetes, hypertension or lipid-lowering medications, and, for females, current use of female hormones. Anthropometric measurements include age, sex, height, weight, hip circumference, waist circumference and derived ratios. Each phenotype variable has an initial summary column containing the most recent non-missing measurement for each individual, followed by the five potential time points for each individual, the number of non-missing measurements, and the age and year for the most recent non-missing measurement. For historical reasons, the order in which variables are presented on the dbGaP web site differs from their order in the data download file. When reading the comment fields for each variable, please note that commas are omitted to support data exchange in .csv format.

  Study phs000462

• Sweden-Schizophrenia Population-Based Case-Control Exome Sequencing

  Current findings of the genetic risk of schizophrenia and bipolar disorder emerging from genome wide association studies (GWAS) support a highly polygenic model displaying the full spectrum of causal alleles that includes the extremes of rare, penetrant alleles as well as common alleles of small effect. Lower frequency polymorphism, rare variants and private mutations have eluded measurement by GWAS studies and thus association with disease. In order to create a comprehensive catalogue of low frequency or rare coding variation in individuals with psychiatric disease and to build a foundation for future genetic studies of schizophrenia and bipolar disorder, we have obtained whole exome DNA sequence from a population-based schizophrenia and bipolar disorder Swedish case-control cohort.

  Study phs000473

• Biology and Molecular Analysis of Human Hematopoiesis Genetics

  In this study we have performed exome sequencing using the hybrid capture method that has previously been described (Gnirke et al., Nature Biotechnology, 2009) on genomic DNA samples from patients with the congenital bone marrow failure syndrome that affects the erythroid lineage, specifically, Diamond-Blackfan anemia. This disease is characterized by a hypoplastic anemia and approximately 50% of cases are attributable to mutations in ribosomal protein gene subunits. The other 50% of cases do not have a known genetic etiology and the purpose of this study is to attempt to delineate such causes.

  Study phs000474

• The molecular basis of inherited reproductive disorders

  The purpose of this study is to discover genetic mutations in patients who have GnRH deficient states. This includes individuals with variant forms of hypogonadotropic hypogonadism, including individuals who have somatic anomalies involving mid-line facial defects, renal agenesis, synkinesia, and ataxia, amongst others.

  Study phs000475

• Molecular defects in pseudohypoparathyroidism or related disorders

  Maintaining calcium levels within a narrow normal range is of critical importance for numerous different cellular functions. One of the most important regulators of blood calcium levels is parathyroid hormone (PTH), which mediates its actions through the PTH/PTHrP receptor, a Gαs-coupled receptor. Few inherited disorders are characterized by diminished blood calcium levels and elevated blood phosphate levels; some of these disorders are caused by too little PTH synthesis and/or secretion (hypoparathyroidism, HP), while others are caused by resistance towards PTH (pseudohypoparathyroidism, PHP). Only few of the inherited forms of HP (<10%) have been defined at the molecular level. In contrast, genetic mutations have been identified for several inherited forms of PHP. For example, PHP type Ia (PHP-Ia) is caused by maternally inherited mutations in those GNAS exons that encode Gαs, while autosomal dominant PHP type Ib (AD-PHP-Ib) is caused by maternal inherited deletions within or up-stream of GNAS, which are associated with abnormal GNAS methylation. However, a large number of patients with PTH-resistance and thus hypocalcemia show GNAS methylation changes, but their underlying genetic defects have not yet been defined at the DNA level. These "sporadic" patients may be affected by an autosomal recessive form of PHP-Ib (AR-PHP-Ib), which is most likely not linked to the GNAS locus. In our studies, we propose to search through exome sequence analyses for novel genetic mutations responsible for novel autosomal dominant forms of HP that are not caused by mutations in the known disease-causing genes; some of these families are large enough to perform genetic linkage studies. We furthermore propose to search for the genetic mutation(s) responsible for the autosomal recessive variant of PHP-Ib through the analysis of whole exome sequences; for these studies we focus particularly on patients, whose parents are likely to be consanguineous. The proposed efforts are expected to lead to the identification of novel genes that are involved in parathyroid development and function (HP) and genes that are involved in the establishment or maintenance of GNAS methylation (AR-PHP-Ib).

  Study phs000476

• Sporadic autism exomes reveal a highly interconnected protein network of de novo mutations

  It is well established that autism spectrum disorders (ASD) have a strong genetic component; however, for at least 70% of cases, the underlying genetic cause is unknown. Under the hypothesis that de novo mutations underlie a substantial fraction of the risk for developing ASD in families with no previous history of ASD or related phenotypes-so-called sporadic or simplex families-we sequenced all coding regions of the genome (the exome) for parent-child trios exhibiting sporadic ASD, including 189 new trios and 20 that were previously reported. Additionally, we also sequenced the exomes of 50 unaffected siblings corresponding to these new (n = 31) and previously reported trios (n = 19), for a total of 617 individual exomes from 209 families deposited in dbGaP. Here we show that de novo point mutations are overwhelmingly paternal in origin (4:1 bias) and positively correlated with paternal age, consistent with the modest increased risk for children of older fathers to develop ASD. Moreover, 39% (49 of 126) of the most severe or disruptive de novo mutations map to a highly interconnected beta-catenin/chromatin remodelling protein network ranked significantly for autism candidate genes. In proband exomes, recurrent protein-altering mutations were observed in two genes: CHD8 and NTNG1. Mutation screening of six candidate genes in 1,703 ASD probands identified additional de novo, protein-altering mutations in GRIN2B, LAMC3 and SCN1A. Combined with copy number variant (CNV) data, these results indicate extreme locus heterogeneity but also provide a target for future discovery, diagnostics and therapeutics.

  Study phs000482

• Genetic defects in familial renal disorders

  Several different genes cause, when mutated, increased urinary phosphate excretion and hypophosphatemia leading to rickets/osteomalacia; however, the majority of phosphate-wasting disorders has not yet been defined at the molecular level. Identification of phosphate-regulating genes has provided important novel insights into the mechanism contributing to phosphate homeostasis, which remains incompletely understood. We therefore pursue exome-wide nucleotide sequence analysis to define the underlying mutations, which is expected to provide novel insights into the regulation of this important mineral. Virtually nothing is known about the genetic mutations that cause non-syndromic structural abnormalities involving the urinary tract, which represent about 50% of the causes of end-stage renal disease (ESRD). The completion of the human genome project and the technological advances that allow low cost whole exome sequencing have now made it feasible to readily search for the cause of different inherited disorders in humans, particularly if clinical information and genomic DNA is available from larger kindreds with multiple affected members that can be used for mapping the disease-causing genetic locus. Furthermore, catalogs were generated that document the expression profiles of numerous genes during embryonic, fetal, and postnatal development, thereby supporting the exploration of kidney involvement in animal models of different diseases and in human genetic syndromes. We therefore plan to define the mechanisms leading to inherited disorders of the urogenital tract and the kidneys by establishing the causative genetic defects through a combination of genetic mapping and whole exome sequencing. Hajdu-Cheney Syndrome (HCS) is a rare autosomal-dominant skeletal disorder characterized by severe osteoporosis, acroosteolysis of the distal phalanges, renal cysts and other abnormalities. Our goal is to identify the genetic cause of HCS using exome sequencing. Opsismodysplasia is a very rare recessive spondylometaphyseal dysplasia characterized by delayed epiphyseal ossification, shortness of bones and sometimes low serum phosphate levels. Discovery of the causing mutation will give us insights into the pathogenesis of this often lethal disease.

  Study phs000477

• Strabismus, CCDD and other anomalies

  Strabismus is one of the most common ophthalmological diseases affecting our population. It has many detrimental effects for affected individuals, including functional visual loss from amblyopia, secondary psychosocial difficulties, and limited employment opportunities. Strabismus also imposes a significant economical burden on society from the cost of screening programs, surgical correction, and lost productivity. Congenital incomitant strabismus is a broad term that encompasses congenital ocular motility disorders with restricted movement in one or more directions of gaze, and includes various forms of Duane's retraction syndrome, horizontal gaze palsy, congenital fibrosis of extraocular muscles, and Moebius syndrome. Incomitant strabismus together with a group of related disorders such as congenital ptosis and congenital facial palsy have been collectively redefined as congenital cranial dysinnervation disorders (CCDDs). This redefinition stemmed from previous studies in the Engle lab showing that these disorders can be caused by mutations in genes encoding transcription factors critical to ocular cranial motor neuron development and by genes that encode proteins essential to the proper growth and guidance of developing axons. Thus, while these disorders account for only a small percent of strabismus, understanding their genetic etiology has led to our ability to provide genetic testing and counseling, and has provided the first insights into the molecular etiologies of strabismus. While the Engle lab has identified all seven CCDD genes published to date, our cohort still includes >100 familial CCDD pedigrees that are mutation-negative. We continue to utilize co-segregation analysis and whole exome or whole genome sequencing technologies to identify new disease genes in this mutation-negative cohort.

  Study phs000478

• Genome-Wide Analysis of Splenic Marginal Zone Lymphoma

  Splenic Marginal Zone Lymphoma (SMZL) is a B-cell malignancy of unknown pathogenesis and thus orphan of targeted therapies. By integrating whole-exome sequencing and copy-number analysis of 8 paired tumor-normal DNAs from patients with SMZL, we show that the typical SMZL exome carries ~30 genetic alterations. Targeted resequencing of selected candidates in an extended panel of 40-117 samples revealed activating mutations of NOTCH2, a gene required for marginal-zone (MZ) development, as the most frequent and SMZL-specific lesion, accounting for approximately 20% of cases. Additional altered genes suggest that deregulation of signaling pathways normally involved in MZ development (NOTCH, NF-kappa B, and B-cell receptor) represents a critical event in SMZL pathogenesis. These findings have direct implications for the treatment of SMZL patients since drugs are available which can target NOTCH as well as other pathways deregulated in this disease.

  Study phs000502