3334 results for "*geneti*"

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• Identification of Rare Germline Variants in Familial Patients with Non-medullary Thyroid Cancer

  As the most common malignancy of the endocrine system, thyroid cancer is classified into two major categories, non-medullary thyroid cancer (NMTC) and medullary thyroid cancer (MTC) according to the origins and clinical features. NMTC includes papillary thyroid cancer (PTC), follicular thyroid cancer (FTC), and anaplastic thyroid cancer (ATC). Sporadic non-medullary thyroid cancer (SNMTC) accounts for ~90% of all thyroid cancers. Compared to SNMTC, familial non-medullary thyroid cancer (FNMTC) is rare, constituting only 3 - 9%. FNMTC is a complex genetic disease that often shows an autosomal dominant mode of inheritance. Characterization of the germline variants causing the disease is still challenging given the heterogeneity of affected families. In recent years, some mutations in known cancer susceptive coding genes have been reported using targeted DNA sequencing method in FNMTC cases. Still, little is known for the novel mutations in other thyroid cancer predisposition genes. With the decreasing cost and rapid development of next generation sequencing technology, more rare germline mutations underlying different types of cancer susceptibility in families had been discovered by whole genome sequencing (WGS). In this study, we performed WGS in familial NMTC patients in the U.S. Our aim is to identify rare germline variants with high penetrance that may contribute to thyroid cancer predisposition in NMTC families.

  Study phs001758

• Center for Common Disease Genomics (CCDG) Neuropsychiatric: Autism Genetic Resource Exchange

  In this study, we address the enormous challenges common complex diseases pose for genomic analysis and the enormous opportunities surmounting them offers for advancing healthcare. The common genetic disorders proposed for study here are believed to have extreme locus heterogeneity, requiring the analysis of large numbers of samples to comprehensively identify the genomic variants underlying them. We propose that a combination of deep population studies and joint analysis of SNPs, indels, and structural variants both in coding and noncoding regions will provide the next level of understanding of common genetic disorders. Whole genome sequencing (WGS) will be critical to this next-generation approach to the genomics of complex disease. WGS will need to be accompanied by the technical ability to generate and handle very large data sets, a particular focus and strength of NYGC. WGS will also need to be accompanied by new statistical tools and algorithms, which will be developed by the strong core group committed to this proposal. An overarching goal of this proposal, one that capitalizes on the power of WGS, is to identify disease-associated variants at the individual nucleotide level. In many cases pathogenic mutations fall in noncoding regions of the genome, which can only be fruitfully explored with WGS. A major effort was put into building new computational strategies to functionally annotate noncoding transcribed sequences, and to build new datasets to enable such strategies, opening new frontiers of understanding of disease-related regulatory variants.

  Study phs001766

• Genomic Diagnosis and Individualized Therapy of Highly Penetrant Genetic Diabetes

  The most common and well-known causes of diabetes are type 1 and type 2 diabetes; however, there are many other etiologies of diabetes. At least 1-2% of diabetes cases result from high penetrance single gene defects, most commonly in a gene encoding either a transcription factor involved in beta cell development and function or the enzyme glucokinase (GCK). Others have mutations in transcription factors necessary for beta cell development and function. This subset of monogenic diabetes cases is autosomal dominant and is known as "Maturity-Onset Diabetes of the Young" (MODY). Patients with type 1 diabetes are insulin dependent, meaning they lack insulin production and therefore require multiple daily injections of insulin, as well as multiple times a day blood glucose monitoring. This can be quite burdensome. Type 2 diabetes is predominantly an insulin resistance problem and can often be managed with pills initially, but there are many who also require insulin either at diagnosis or later on in their disease course. Usually, monogenic diabetes is misdiagnosed as type 1 or type 2 diabetes and thus treated suboptimally. Those with monogenic diabetes, due to a defect in a gene encoding a transcription factor, respond extremely well to a class of oral diabetes medications called sulfonylureas. Those with GCK-MODY often have a mild, stable, fasting, nonprogressive hyperglycemia for which pharmacological treatment is often not necessary. It is important to accurately diagnose our patients with the correct etiology to their diabetes for a multitude of reasons. Accurately diagnosing a patient with MODY, for example, can predict their clinical course and we can tailor treatment accordingly. If diagnosed with a transcription factor MODY, we can try switching the patient from insulin to an oral sulfonylurea, and if diagnosed with a GCK-MODY, we can consider discontinuing pharmacological treatment altogether. With specific tailoring of treatment, we would hope to improve quality of life by discontinuing perhaps multiple daily injections of insulin and glucose checking as these may not be necessary. In addition, we would hope to improve glycemic control with an eventual decreased cost to society by decreasing the complication rate of diabetes, resulting in less specialty referrals, lab tests, supplies and procedures. Further, given MODY is an autosomal dominant condition with a 50% chance of inheritance to first-degree family members, we could offer testing to asymptomatic family members which could lead to prevention and/or early diagnosis and treatment. Overall, testing for monogenic diabetes is underutilized clinically. Testing is being done in the U.K., but in the U.S. we are lagging behind. This is most predominantly due to lack of knowledge and concern over cost. In addition, it is difficult to differentiate the relatively small number of monogenic diabetes cases from the larger number with type 1 and type 2 diabetes as each of these etiologies have overlapping characteristics. In fact, many patients with monogenic diabetes are being misdiagnosed with type 1 and type 2 diabetes. There are recommendations set forth by different societies on who to consider screening for monogenic diabetes. However, these recommendations are difficult to employ clinically as they are general recommendations, there is no specific algorithm, and they are based on varying levels of evidence. The purpose of this study is to implement a personalized diabetes medicine program to enhance the identification of individuals and families affected by highly penetrant diabetes gene mutations through a combination of systematic screening and genetic testing at the University of Maryland Center for Diabetes and Endocrinology, the Baltimore VA Medical Center and additional partner centers at Geisinger Health System and Bay West Endocrinology Associates, and other UM outpatient clinics. Our hope is to develop an approach that can be eventually implemented across the United States so that we can more often uncover the correct etiology to diabetes, tailor treatment accordingly, and test asymptomatic family members.

  Study phs001771

• Effect of the Placental Transcriptome on Stunting in a Longitudinal African Cohort

  Mammals with placentas and flowering plants evolved genomic imprinting in nutritive tissues, the placenta and endosperm, respectively. In these tissues, the genomes inherited from the mother and father are in conflict over resource allocation to offspring. In imprinted genes, transcription is repressed on the paternal or the maternal allele, resulting in allele specific expression (ASE). We investigated the variation in ASE of imprinted genes in term human placentas in order to detect loss of imprinting (LOI), which leads to partial expression of the repressed allele. We collected the placental tissue from birth to women in our multigenerational, prospective cohort study in Mali, West Africa. We followed the women from their own infancies, early childhood to adulthood (age 18+ years). Contingent on prior informed consent, we collected placental tissue and umbilical cord tissue. We conducted RNA-Seq of the fetal compartment of the placentas and targeted DNA-Seq of the umbilical cord tissue, which is fetal, and of saliva samples from parents. Our sequencing effort produced two datasets. The first dataset is the whole transcriptome RNA-Seq dataset of 111 biopsies (59 placentas) and genotyping of 96 genes. Birth length, weight, and placental weight for the children associated with this dataset are listed in the phenotype file (DOI: 10.1093/molbev/msz226). The second dataset includes targeted RNA-Seq of 262 samples (251 placentas) and targeted DNA-Seq for 766 genes. The genes were selected because they met any one of the following criteria: (1) imprinted and reported in some studies, (2) highly expressed in placenta, or (3) relevant to diseases of interest in this cohort (https://doi.org/10.1093/g3journal/jkab176). This study provides the first systematic analysis of variation in LOI across genes and individuals in a human population, and should shed light on the hypothesis that the modulation of imprinting is an epigenetic mechanism and plays a role in the regulation of offspring growth.

  Study phs001782

• Center for Inherited Disease Research (CIDR)-National Institute on Aging (NIA) Whole Exome Analysis of Ehlers-Danlos Syndrome

  The Ehlers-Danlos syndromes (EDS) are a family of hereditary disorders of connective tissue characterized by joint hypermobility and skin involvement with soft, translucent, stretchy skin, and atrophic scarring. To date, over 12 different types of EDS are known, and the genes causing almost all of them have been found. However, the gene(s) underlying the most common of Ehlers-Danlos syndrome, known as the hypermobile type, remain elusive. The hypermobile type of Ehlers-Danlos syndrome is associated with multiple co-morbidities, including dysautonomia, chronic musculoskeletal pain, gastrointestinal dysmotility, mast cell activation and multiple neurologic complications. Affected persons often suffer from chronic fatigue and may be chronically disabled. While the precise frequency of the condition is not known, it may be as common as between 1/500 and 1/1000 persons. There is a significant overlap with the phenotype of fibromyalgia, and multiple persons diagnosed with fibromyalgia may well have the hypermobile type of Ehlers-Danlos syndrome. The phenotype of hypermobile EDS segregates as a single dominant trait with complete penetrance, variable expressivity, and a markedly evolving phenotype over time. Identification of the genetic cause of this hereditary disorder has the potential to inform rational therapy for this disabling condition. It is hoped that the insight into the pathogenesis of the hypermobile type of EDS will lead to a similar breakthrough in therapy for this disorder. Toward this end, whole exome sequencing (WES) of DNA from a total of 167 patients will be performed at the Center for Inherited Disease Research (CIDR) to identify genes underlying the hypermobile type of Ehlers-Danlos syndrome and those with EDS of an uncharacterized type.

  Study phs001779

• Genetics of Fuchs Corneal Dystrophy

  This grant proposal continues to expand our understanding of the clinical presentation of Fuchs corneal dystrophy, and its underlying genetic basis, which will lead to the development of better therapeutic models and treatment for a common corneal dystrophy that affects 4% of the US population over age 40.

  Study phs001834

• Discovery of Colorectal Cancer Susceptibility Genes in High-Risk Families

  Colorectal cancer remains one of the most common cancers in the US with 146,970 new diagnoses and 49,920 deaths estimated for 2009. Colon cancer is also one of the most familial of cancers. Individuals with a first-degree relative with colon cancer have a 2- to 3-fold increased risk, and those with more than one first-degree relative with colon cancer, or a single first-degree relative affected at age 50 years, have a 3- to 6-fold greater risk than those with no family history. The most prominent high-risk colorectal cancer susceptibility genes, APC, MLH1, MSH2, MSH6, and PTEN, were all discovered more than a decade ago. Currently, mutation screening of these genes, plus a short list of additional genes that are responsible for a very small fraction of colorectal cancer, plays an important role in the clinical management of individuals with a strong family history of the disease or syndromic evidence for the presence of a gene mutation. At the other end of the risk spectrum, genome-wide association studies have identified a number of common alleles with very modest effects on colorectal cancer risk; their clinical utility has yet to be established. However, taken together, the known spectrum of genetic effects only explain about one quarter of the overall familial excess of colorectal cancer. It should be emphasized that, at present, the vast majority of individuals seen at familial cancer clinics are counseled on the basis of their family history alone because they do not have mutations in the known susceptibility genes. Accordingly, the long-term objective of this project is to identify the majority of genes responsible for the unexplained component of inherited colorectal cancer risk. Nextgen DNA sequencing is well suited for application to research questions in genetic susceptibility for which linkage analysis is confounded by extensive genetic heterogeneity. Taking advantage of unparalleled familial cancer genetics resources available through the Utah Population Database, candidate genes have been identified by sequencing all of the gene exons in the human genome from a series of colorectal cancer cases with a very strong family history of colorectal cancer not explained by one of the currently known high-risk susceptibility genes.

  Study phs001787

• Intergenerational Impact of Genetic and Psychological Factors on Blood Pressure (InterGEN Study)

  This research study focuses on the genomic and psychological environmental effects on blood pressure among mothers and their children. The study includes 250 mothers who self-identify as AA/black, and 250 children between the ages of 3 and 5 years old at the time of enrollment. The study is longitudinal and data collection interviews are scheduled every six months for two years after enrollment, for a total of four participant interviews. Assessment is as follows: genetic (time 1 only) and psychological factors (every six months for two years).

  Study phs001792

• Genetic Analysis of the Chiari I Malformation

  This study used whole exome sequencing (WES) on families affected with Chiari I Malformation (CM1). Individuals were recruited from the Republic of Tartarstan in the Russian Federation, where CM1 has a high prevalence (approximately 413 out of 100,000). At least one-third of these affected individuals have an affected relative. In collaboration with Dr. Enver Bogdanov of Kazan State Medical University, seven extended families affected with CM1 were identified. Eligible participants for this study were required to 1) have CM1 and a family member with syringomyelia or CM1, or 2) be a family member of a patient with CM1 and have at least two immediate family members diagnosed with CM1. Adults and minors were eligible for this study and recruitment was through self and physician referral. Patients were excluded if they had a contraindication to MRI scanning, were unable to understand the risks of testing, were under one year of age, or could not undergo MRI scanning without sedation. Study participants underwent SPGR (Spoiled Gradient Recalled) and T1-weighted MR-imaging of the brain and cervical spinal cord to assess the volume of the posterior fossa, as well as the presence of CM1. Individuals were defined as having CM1 if the inferior aspect of the cerebellar tonsils were lying ≥=2 mm caudal to the foramen magnum. Individuals were defined as having a small posterior fossa volume if the ratio of the posterior fossa volume to the supratentorial volume was < 0.15. Sixty-two patients (both cases and controls) from the seven extended families had DNA extracted from blood lymphocytes contained in 10 milliliters of stored blood. Whole exome sequencing (WES) was performed by the National Intramural Sequencing Center (NISC). These genotype data, as well as the case-control phenotype data on CM1 diagnosis and small posterior fossa diagnosis, were made available to dbGaP.

  Study phs001795

• A New Reference Panel to Boost African American Genotype Imputation

  Modern genetic studies have been conducted predominantly in cohorts of individuals of European ancestry. By 2010, there were approximately ten times as many published genome wide association studies (GWAS) in people of European ancestry than studies in people of all other ancestries combined. This research disparity has led to an uneven understanding of the genetic basis underlying disease in Europeans and non-Europeans. 23andMe's web-based, large scale research model is ideal for scaling genetics research within non-European populations and thereby bringing more parity to genetics research. Our database is composed of genotypes and phenotypes of over 1,000,000 consenting customers, including over 200,000 individuals with non-European ancestry. The data derived from non-European individuals represent a particularly valuable resource for genetic discovery of novel variants that may not be found in the European population. However, research studies in non-European populations are weakened by the lack of availability of large-scale reference datasets and, in particular, genotype imputation panels. Genotype imputation is a statistical methodology that uses observations of genotypes in a large reference panel to infer unobserved genotypes in a target dataset. This methodology is widely used within GWAS, and allows novel genetic associations to be identified and refined. Due to this utility, very large reference panels have been constructed, containing thousands or tens of thousands of whole genome sequences. Unfortunately, the largest imputation panels are composed of predominantly European genomes, reflecting the modern bias towards European studies in GWAS. This proposal aims to address this imbalance by constructing an imputation panel specifically for the African American population. In doing so, we will expand 23andMe's ability to perform genetic discovery in non-European populations, and improve the understanding of global genetic variation underlying diseases and traits. Key commercial outcomes of the research include the identification of novel genetic targets for internal and external therapeutic development. The long-term aim is to improve understanding of disease in minority populations, which we hope may eventually lead to improved treatments of disease in these historically medically understudied groups.

  Study phs001798