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PURPOSE: Genetic variants at the low end of the penetrance spectrum have historically been challenging to interpret because their high population frequencies exceed the disease prevalence of the associated condition, leading to a lack of clear segregation between the variant and disease. There is currently substantial variation in the classification of these variants, and no formal classification framework has been widely adopted. The Clinical Genome Resource Low Penetrance/Risk Allele Working Group was formed to address these challenges and promote harmonization within the clinical community. METHODS: The work presented here is the product of internal and community Likert-scaled surveys in combination with expert consensus within the Working Group. RESULTS: We formally recognize risk alleles and low-penetrance variants as distinct variant classes from those causing highly penetrant disease that require special considerations regarding their clinical classification and reporting. First, we provide a preferred terminology for these variants. Second, we focus on risk alleles and detail considerations for reviewing relevant studies and present a framework for the classification these variants. Finally, we discuss considerations for clinical reporting of risk alleles. CONCLUSION: These recommendations support harmonized interpretation, classification, and reporting of variants at the low end of the penetrance spectrum.
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Variación Genética , Humanos , Alelos , Variación Genética/genética , Penetrancia , Frecuencia de los GenesRESUMEN
Genome-wide association studies (GWAS) of mood disorders in large case-control cohorts have identified numerous risk loci, yet pathophysiological mechanisms remain elusive, primarily due to the very small effects of common variants. We sought to discover risk variants with larger effects by conducting a genome-wide association study of mood disorders in a founder population, the Old Order Amish (OOA, n = 1,672). Our analysis revealed four genome-wide significant risk loci, all of which were associated with >2-fold relative risk. Quantitative behavioral and neurocognitive assessments (n = 314) revealed effects of risk variants on sub-clinical depressive symptoms and information processing speed. Network analysis suggested that OOA-specific risk loci harbor novel risk-associated genes that interact with known neuropsychiatry-associated genes via gene interaction networks. Annotation of the variants at these risk loci revealed population-enriched, non-synonymous variants in two genes encoding neurodevelopmental transcription factors, CUX1 and CNOT1. Our findings provide insight into the genetic architecture of mood disorders and a substrate for mechanistic and clinical studies.
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Diabetes mellitus is a group of diseases characterized by hyperglycemia and its consequences, affecting over 34 million individuals in the United States and 422 million worldwide. While most diabetes is polygenic and is classified as type 1 (T1D), type 2 (T2D), or gestational diabetes (GDM), at least 0.4% of all diabetes is monogenic in nature. Correct diagnosis of monogenic diabetes has important implications for glycemic management and genetic counseling. We provide this Practice Resource to familiarize the genetic counseling community with (1) the existence of monogenic diabetes, (2) how it differs from more common polygenic/complex diabetes types, (3) the advantage of a correct diagnosis, and (4) guidance for identifying, counseling, and testing patients and families with suspected monogenic diabetes. This document is intended for genetic counselors and other healthcare professionals providing clinical services in any setting, with the goal of maximizing the likelihood of a correct diagnosis of monogenic diabetes and access to related care.
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Genetically isolated populations that arise due to recent bottleneck events have reduced genetic variation reflecting the common set of founders. Increased genetic relatedness among members of isolated populations puts them at increased risk for some recessive disorders that are rare in outbred populations. To assess the burden on reproductive health, we compared frequencies of adverse reproductive outcomes between Amish couples who were both heterozygous carriers of a highly penetrant pathogenic or likely pathogenic variant and noncarrier couples from the same Amish community. In addition, we evaluated whether overall genetic relatedness of parents was associated with reproductive outcomes. Of the 1824 couples included in our study, 11.1% were at risk of producing a child with an autosomal recessive disorder. Carrier couples reported a lower number of miscarriages compared to noncarrier couples (p = 0.02), although the number of stillbirths (p = 0.3), live births (p = 0.9), and number of pregnancies (p = 0.9) did not differ significantly between groups. In contrast, higher overall relatedness between spouses was positively correlated with number of live births (p < 0.0001), pregnancies (p < 0.0001), and stillbirths (p = 0.03), although not with the number of miscarriages (p = 0.4). These results highlight a complex association between relatedness of parents and reproductive health outcomes in this community.
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Aborto Espontáneo , Amish , Aborto Espontáneo/epidemiología , Aborto Espontáneo/genética , Amish/genética , Femenino , Heterocigoto , Humanos , Recién Nacido , Padres , Embarazo , Mortinato/epidemiología , Mortinato/genéticaRESUMEN
BACKGROUND AND PURPOSE: Muscular A-type lamin-interacting protein (MLIP) is most abundantly expressed in cardiac and skeletal muscle. In vitro and animal studies have shown its regulatory role in myoblast differentiation and in organization of myonuclear positioning in skeletal muscle, as well as in cardiomyocyte adaptation and cardiomyopathy. We report the association of biallelic truncating variation in the MLIP gene with human disease in five individuals from two unrelated pedigrees. METHODS: Clinical evaluation and exome sequencing were performed in two unrelated families with elevated creatine kinase level. RESULTS: Family 1. A 6-year-old girl born to consanguineous parents of Arab-Muslim origin presented with myalgia, early fatigue after mild-to-moderate physical exertion, and elevated creatine kinase levels up to 16,000 U/L. Exome sequencing revealed a novel homozygous nonsense variant, c.2530C>T; p.Arg844Ter, in the MLIP gene. Family 2. Three individuals from two distantly related families of Old Order Amish ancestry presented with elevated creatine kinase levels, one of whom also presented with abnormal electrocardiography results. On exome sequencing, all showed homozygosity for a novel nonsense MLIP variant c.1825A>T; p.Lys609Ter. Another individual from this pedigree, who had sinus arrhythmia and for whom creatine kinase level was not available, was also homozygous for this variant. CONCLUSIONS: Our findings suggest that biallelic truncating variants in MLIP result in myopathy characterized by hyperCKemia. Moreover, these cases of MLIP-related disease may indicate that at least in some instances this condition is associated with muscle decompensation and fatigability during low-to-moderate intensity muscle exertion as well as possible cardiac involvement.
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Cardiomiopatías , Enfermedades Musculares , Adaptación Fisiológica , Animales , Humanos , Enfermedades Musculares/genética , Mialgia , LinajeAsunto(s)
Diabetes Mellitus , Enfermedades Renales Quísticas , Humanos , Masculino , Adulto Joven , Quistes , Riñón/diagnóstico por imagenRESUMEN
Founder populations may be enriched with certain genetic variants of high clinical impact compared to nonfounder populations due to bottleneck events and genetic drift. Using exome sequencing (ES), we quantified the load of pathogenic variants that may be clinically actionable in 6136 apparently healthy adults living in the Lancaster, PA Old Order Amish settlement. We focused on variants in 78 genes deemed clinically actionable by the American College of Medical Genetics and Genomics (ACMG) or Geisinger's MyCode Health Initiative. ES revealed 3191 total variants among these genes including 480 nonsynonymous variants. After quality control and filtering, we applied the ACMG/AMP guidelines for variant interpretation and classified seven variants, across seven genes, as either pathogenic or likely pathogenic. Through genetic drift, all seven variants, are highly enriched in the Amish compared to nonfounder populations. In total, 14.7% of Lancaster Amish individuals carry at least one of these variants, largely explained by the 13% who harbor a copy of a single variant in APOB. Other studies report combined frequencies of pathogenic/likely pathogenic (P/LP) variants in actionable genes between 2.0% and 6.2% in outbred populations. The Amish population harbors fewer actionable variants compared to similarly characterized nonfounder populations but have a higher frequency of each variant identified, offering opportunities for efficient and cost-effective targeted precision medicine.
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Enfermedades Genéticas Congénitas/genética , Predisposición Genética a la Enfermedad , Genómica , Adulto , Amish/genética , Exoma/genética , Femenino , Enfermedades Genéticas Congénitas/diagnóstico , Enfermedades Genéticas Congénitas/epidemiología , Pruebas Genéticas , Variación Genética/genética , Humanos , Masculino , Persona de Mediana Edad , Medicina de Precisión , Secuenciación del ExomaRESUMEN
A major challenge in evaluating the contribution of rare variants to complex disease is identifying enough copies of the rare alleles to permit informative statistical analysis. To investigate the contribution of rare variants to the risk of type 2 diabetes (T2D) and related traits, we performed deep whole-genome analysis of 1,034 members of 20 large Mexican-American families with high prevalence of T2D. If rare variants of large effect accounted for much of the diabetes risk in these families, our experiment was powered to detect association. Using gene expression data on 21,677 transcripts for 643 pedigree members, we identified evidence for large-effect rare-variant cis-expression quantitative trait loci that could not be detected in population studies, validating our approach. However, we did not identify any rare variants of large effect associated with T2D, or the related traits of fasting glucose and insulin, suggesting that large-effect rare variants account for only a modest fraction of the genetic risk of these traits in this sample of families. Reliable identification of large-effect rare variants will require larger samples of extended pedigrees or different study designs that further enrich for such variants.
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Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad/genética , Variación Genética , Americanos Mexicanos/genética , Diabetes Mellitus Tipo 2/etnología , Diabetes Mellitus Tipo 2/patología , Salud de la Familia , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad/etnología , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Humanos , Masculino , Linaje , Fenotipo , Sitios de Carácter Cuantitativo/genética , Secuenciación Completa del Genoma/métodosRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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INTRODUCTION: Previous research has suggested that the Amish may experience a relatively high prevalence of Parkinson's disease (PD) and/or parkinsonian motor signs. METHODS: In a large sample from the Amish community in Lancaster County, Pennsylvania, age ≥18 years, we assessed the prevalence of self-reported PD diagnosis. For those without self-reported PD diagnosis, we assessed the frequency of PD-related motor symptoms using a 9-item questionnaire that was designed by the PD Epidemiology Research Group. Lastly, we queried study participants for the presence of 2 nonmotor symptoms that have been commonly linked to PD: bowel movement frequency and daytime sleepiness. RESULTS: Among 2,025 subjects who answered the PD questionnaire, 430 were older than 60 years. Of 430 participants ≥60 years, 5 (1.2%) reported a PD diagnosis. Of those without a PD diagnosis, 10.5% reported ≥1 and 1.2% ≥ 4 motor symptoms for the 9-item PD screening questionnaire. Of the 3,789 subjects who answered the question about bowel movement frequency, 0.7% reported ≤3 bowel movements per week. Among 1,710 subjects who answered the question about daytime sleepiness, 8.1% of the participants reported "always" sleepy during the day. DISCUSSION: These data neither support a markedly higher PD prevalence in the older Lancaster Amish nor do they show dramatically higher motor and/or selected nonmotor symptoms than the general population. Future studies that employ more rigorous procedures for case identification and PD-specific preclinical symptoms/tests are needed to determine the potential differences and similarities among different Amish populations and between Amish and non-Amish populations.
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Amish , Enfermedad de Parkinson/etnología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estreñimiento/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/epidemiología , Pennsylvania , Proyectos Piloto , Prevalencia , Somnolencia , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Objective- Apo (apolipoprotein) CIII inhibits lipoprotein lipase (LpL)-mediated lipolysis of VLDL (very-low-density lipoprotein) triglyceride (TG) and decreases hepatic uptake of VLDL remnants. The discovery that 5% of Lancaster Old Order Amish are heterozygous for the APOC3 R19X null mutation provided the opportunity to determine the effects of a naturally occurring reduction in apo CIII levels on the metabolism of atherogenic containing lipoproteins. Approach and Results- We conducted stable isotope studies of VLDL-TG and apoB100 in 5 individuals heterozygous for the null mutation APOC3 R19X (CT) and their unaffected (CC) siblings. Fractional clearance rates and production rates of VLDL-TG and apoB100 in VLDL, IDL (intermediate-density lipoprotein), LDL, apo CIII, and apo CII were determined. Affected (CT) individuals had 49% reduction in plasma apo CIII levels compared with CCs ( P<0.01) and reduced plasma levels of TG (35%, P<0.02), VLDL-TG (45%, P<0.02), and VLDL-apoB100 (36%, P<0.05). These changes were because of higher fractional clearance rates of VLDL-TG and VLDL-apoB100 with no differences in production rates. CTs had higher rates of the conversion of VLDL remnants to LDL compared with CCs. In contrast, rates of direct removal of VLDL remnants did not differ between the groups. As a result, the flux of apoB100 from VLDL to LDL was not reduced, and the plasma levels of LDL-cholesterol and LDL-apoB100 were not lower in the CT group. Apo CIII production rate was lower in CTs compared with CCs, whereas apo CII production rate was not different between the 2 groups. The fractional clearance rates of both apo CIII and apo CII were higher in CTs than CCs. Conclusions- These studies demonstrate that 50% reductions in plasma apo CIII, in otherwise healthy subjects, results in a significantly higher rate of conversion of VLDL to LDL, with little effect on direct hepatic uptake of VLDL. When put in the context of studies demonstrating significant protection from cardiovascular events in individuals with loss of function variants in the APOC3 gene, our results provide strong evidence that therapies which increase the efficiency of conversion of VLDL to LDL, thereby reducing remnant concentrations, should reduce the risk of cardiovascular disease.
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Apolipoproteína C-III/fisiología , Lípidos/sangre , Lipoproteínas/metabolismo , Adulto , Anciano , Apolipoproteína B-100/metabolismo , Apolipoproteína C-III/deficiencia , Apolipoproteína C-III/genética , Femenino , Humanos , Lipólisis , Lipoproteínas IDL/metabolismo , Lipoproteínas VLDL/metabolismo , Masculino , Persona de Mediana Edad , MutaciónRESUMEN
Most monogenic diabetes is misdiagnosed as either type 1 or type 2 diabetes (T1D/T2D). Few studies have examined the diagnostic challenges from the patients' perspective. This qualitative study aimed to investigate patients' journeys to obtaining a diagnosis of maturity-onset diabetes of the young (MODY) by elucidating the range of factors that can act as barriers and facilitators throughout this process. We recruited participants from the Personalized Diabetes Medicine Program (PDMP) at University of Maryland and used respondent-driven sampling to recruit additional patients. We conducted qualitative phone interviews between October 2016 and June 2017 with nine patients with diagnoses of monogenic diabetes (one HNF4A-MODY, seven GCK-MODY, and one HNF1A-MODY) and one parent of a patient with INS-MODY. Interview data were audio recorded, transcribed, and analyzed both inductively and deductively using thematic content analysis. All patients were female, with a mean age of 35 (range: 7-67 years). The amount of time these patients were misdiagnosed ranged from a few months to 41 years. We identified barriers and facilitators in three broad themes: (a) patient-related (nature of MODY symptoms, perceived test utility, individual personality); (b) provider-related (provider awareness and knowledge, provider communication); and (c) healthcare system-related (cost of testing, access to knowledgeable providers, patient education, and support resources). The diverse range of barriers and facilitators reiterates the complexity of the MODY diagnostic process. Limited awareness and knowledge of MODY from healthcare professionals and patients themselves account for most diagnostic delays described in this study. Efforts to promote awareness of MODY and expand access to screening and testing may result in quicker diagnosis and ensure the downstream benefits of proper treatment.
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Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/psicología , Adolescente , Adulto , Anciano , Niño , Diabetes Mellitus Tipo 2/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Adulto JovenRESUMEN
Familial hypercholesterolemia (FH) is the most common inherited form of high cholesterol that significantly increases the risk for coronary artery disease. Early detection and treatment can decrease morbidity and mortality and provide important risk information to family members. However, FH remains vastly underdiagnosed and undertreated. Cascade screening is the process of iteratively testing first-degree relatives for a genetic disease. It has been shown to effectively identify individuals with undiagnosed FH. The majority of research on methods for cascade screening has been conducted outside of the United States (U.S.). For indirect contact, index cases encourage relatives to undergo testing, and for direct contact, healthcare providers (HCP) obtain the index case's consent to contact relatives and offer information. Currently, there is not an accepted strategy for cascade screening programs in the U.S. This study investigated perspectives on direct and indirect contact for cascade screening from individuals with FH. An online survey was designed in collaboration with the Familial Hypercholesterolemia Foundation (FHF). Fifty-eight percent of U.S. index cases (11/19, 57.9%) and all international index cases (8/8, 100%) indicated willingness to provide contact information for certain at-risk relatives to a HCP for the purpose of directly informing relatives of their risk for FH in a hypothetical scenario. These findings provide an example of U.S. data and additional international data suggesting that some individuals with FH may consider direct contact a reasonable approach to improve screening uptake among family members. These initial findings need further confirmation in a larger group.
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Hiperlipoproteinemia Tipo II/diagnóstico , Tamizaje Masivo/psicología , Adulto , Diagnóstico Precoz , Femenino , Pruebas Genéticas/métodos , Humanos , Hiperlipoproteinemia Tipo II/complicaciones , Hiperlipoproteinemia Tipo II/genética , Masculino , Tamizaje Masivo/métodos , Persona de Mediana EdadRESUMEN
PURPOSE: Research on genomic medicine integration has focused on applications at the individual level, with less attention paid to implementation within clinical settings. Therefore, we conducted a qualitative study using the Consolidated Framework for Implementation Research (CFIR) to identify system-level factors that played a role in implementation of genomic medicine within Implementing GeNomics In PracTicE (IGNITE) Network projects. METHODS: Up to four study personnel, including principal investigators and study coordinators from each of six IGNITE projects, were interviewed using a semistructured interview guide that asked interviewees to describe study site(s), progress at each site, and factors facilitating or impeding project implementation. Interviews were coded following CFIR inner-setting constructs. RESULTS: Key barriers included (1) limitations in integrating genomic data and clinical decision support tools into electronic health records, (2) physician reluctance toward genomic research participation and clinical implementation due to a limited evidence base, (3) inadequate reimbursement for genomic medicine, (4) communication among and between investigators and clinicians, and (5) lack of clinical and leadership engagement. CONCLUSION: Implementation of genomic medicine is hindered by several system-level barriers to both research and practice. Addressing these barriers may serve as important facilitators for studying and implementing genomics in practice.
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Genética Médica , Genómica , Actitud Frente a la Salud , Registros Electrónicos de Salud , Genética Médica/tendencias , Genómica/tendencias , Humanos , Ciencia de la Implementación , Aceptación de la Atención de Salud , Investigación CualitativaRESUMEN
PurposeMonogenic diabetes accounts for 1-2% of diabetes cases. It is often undiagnosed, which may lead to inappropriate treatment. This study was performed to estimate the prevalence of monogenic diabetes in a cohort of overweight/obese adolescents diagnosed with type 2 diabetes (T2D).MethodsSequencing using a custom monogenic diabetes gene panel was performed on a racially/ethnically diverse cohort of 488 overweight/obese adolescents with T2D in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) clinical trial. Associations between having a monogenic diabetes variant and clinical characteristics and time to treatment failure were analyzed.ResultsMore than 4% (22/488) had genetic variants causing monogenic diabetes (seven GCK, seven HNF4A, five HNF1A, two INS, and one KLF11). Patients with monogenic diabetes had a statistically, but not clinically, significant lower body mass index (BMI) z-score, lower fasting insulin, and higher fasting glucose. Most (6/7) patients with HNF4A variants rapidly failed TODAY treatment across study arms (hazard ratio = 5.03, P = 0.0002), while none with GCK variants failed treatment.ConclusionThe finding of 4.5% of patients with monogenic diabetes in an overweight/obese cohort of children and adolescents with T2D suggests that monogenic diabetes diagnosis should be considered in children and adolescents without diabetes-associated autoantibodies and maintained C-peptide, regardless of BMI, as it may direct appropriate clinical management.
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Diabetes Mellitus Tipo 2/genética , Adolescente , Índice de Masa Corporal , Niño , Estudios de Cohortes , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Quinasas del Centro Germinal , Factor Nuclear 1-alfa del Hepatocito/genética , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Factor Nuclear 4 del Hepatocito/genética , Factor Nuclear 4 del Hepatocito/metabolismo , Humanos , Masculino , Obesidad/complicaciones , Obesidad/genética , Sobrepeso/complicaciones , Sobrepeso/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismoRESUMEN
PurposeImplementation research provides a structure for evaluating the clinical integration of genomic medicine interventions. This paper describes the Implementing Genomics in Practice (IGNITE) Network's efforts to promote (i) a broader understanding of genomic medicine implementation research and (ii) the sharing of knowledge generated in the network.MethodsTo facilitate this goal, the IGNITE Network Common Measures Working Group (CMG) members adopted the Consolidated Framework for Implementation Research (CFIR) to guide its approach to identifying constructs and measures relevant to evaluating genomic medicine as a whole, standardizing data collection across projects, and combining data in a centralized resource for cross-network analyses.ResultsCMG identified 10 high-priority CFIR constructs as important for genomic medicine. Of those, eight did not have standardized measurement instruments. Therefore, we developed four survey tools to address this gap. In addition, we identified seven high-priority constructs related to patients, families, and communities that did not map to CFIR constructs. Both sets of constructs were combined to create a draft genomic medicine implementation model.ConclusionWe developed processes to identify constructs deemed valuable for genomic medicine implementation and codified them in a model. These resources are freely available to facilitate knowledge generation and sharing across the field.
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Atención a la Salud/métodos , Medicina de Precisión/métodos , Femenino , Genómica , Humanos , Masculino , Medicina de Precisión/normas , Encuestas y CuestionariosRESUMEN
PURPOSE OF REVIEW: Great strides have recently been made in elucidating the role of genetic sequence variation in diabetes pathogenesis. Increasingly, studies are focusing on other factors that may contribute to the pathogenesis of diabetes, such as epigenetics, a term "traditionally" encompassing changes to the DNA that do not alter sequence and are heritable (primary methylation and histone modification) but often expanded to include microRNAs. This review summarizes latest findings on the role of epigenetics in diabetes pathogenesis. RECENT FINDINGS: Recent studies illustrate roles for methylation changes, histone modification, imprinting, and microRNAs across several diabetes types and complications. Notably, methylation changes in the human leukocyte antigen (HLA) region have been found to precede the development of type 1 diabetes. In type 2 diabetes, lifestyle factors appear to interact with epigenetic mechanisms in pathogenesis. Emerging technologies have allowed increasingly comprehensive descriptive analysis of the role of epigenetic mechanisms in diabetes pathogenesis which have yielded meaningful insights into effects on expression of relevant genes. These findings have the potential to inform future development of predictive testing to enable primary prevention and further work to uncover the complex pathogenesis of diabetes.
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Diabetes Mellitus/genética , Epigénesis Genética , Metilación de ADN/genética , Impresión Genómica , Histonas/metabolismo , Humanos , MicroARNs/genética , MicroARNs/metabolismoRESUMEN
PURPOSE OF REVIEW: To provide an update on knowledge the role of genetics in youth-onset type 2 diabetes (T2D). RECENT FINDINGS: The prevalence in youth of T2D, once thought to be exclusively a disease of adults, has increased by over 35% since 2001. Youth with T2D tend to have higher rates of complications, more aggressive disease, with more rapid loss of beta-cell function and a less favorable response to treatment than adults. Obesity is the most important risk factor for T2D, and the rise in childhood overweight and obesity appears responsible for the dramatic increase in T2D in youth. However, some obese children do not develop T2D, consistent with genetic differences in susceptibility to the disease in the setting of obesity and insulin resistance, currently far less well characterized in youth than in adults. Recent studies have begun to show associations of several established adult T2D genetic risk variants with youth-onset T2D and related glycemic quantitative traits, including the strongest known cross-population T2D genetic contributor TCF7L2. Maturity-onset diabetes of the young (MODY), a diabetes subtype distinct from type 1 diabetes (T1D) and T2D, is now known to result from a highly penetrant gene mutation in one of several genes. MODY has been shown to account for or contribute to at least 4.5% of clinically diagnosed T2D, even among those who are overweight or obese, impacting treatment decisions. The recently formed ProDiGY (Progress in Diabetes Genetics in Youth) Consortium is using genome-wide association studies and whole exome sequencing to understand the genetic architecture of T2D in youth, including how it differs from that of adults. The limited amount of research conducted to date on the genetics of youth-onset T2D, which tends to be a more aggressive disease than adult T2D, suggests some overlap with genes involved in adult T2D and a sizeable influence of highly penetrant monogenic diabetes variants. The ProDiGY Consortium is expected to provide a more comprehensive understanding of youth T2D genetics.
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Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad , Adolescente , Edad de Inicio , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatología , Estudio de Asociación del Genoma Completo , Humanos , Mutación/genética , Factores de RiesgoRESUMEN
The purpose of this study was to assess the informational content, readability, suitability and comprehensibility of websites offering educational information about monogenic diabetes available to patients. The top 20 results from 15 queries in four search engines were screened. Content analysis was performed by two independent coders. Readability was determined using Flesch-Kincaid grade level (FKGL) and Simplified Measure of Goobledygook (SMOG). The Comprehensibility Assessment of Materials (SAM + CAM) scale was utilized to evaluate website suitability and comprehensibility. Only 2% (N = 29) of 1200 screened websites met inclusion criteria. Content analysis showed that 16 websites presented information on at least the most common forms of MODY (1, 2 and 3), four addressed the utility of genetic counseling, and none included support resources for patients. All websites exceeded the consensus readability level (6th grade) as assessed by FKGL (10.1 grade) and SMOG (12.8 ± 1.5 grades). Although the majority (N = 20) of websites had an overall "adequate" to "superior" quality score (SAM + CAM score > = 40%), more than one-third scored "not suitable" in categories of content, literacy demand, graphics, and learning motivation. The online educational resources for monogenic diabetes have a high readability level and require improvement in ease of use and comprehensibility for patients with diabetes.
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Diabetes Mellitus , Alfabetización en Salud/normas , Internet/normas , Educación del Paciente como Asunto/normas , Comprensión , HumanosRESUMEN
Lipoprotein (a) [Lp(a)] is an independent risk factor for atherosclerosis-related events that is under strong genetic control (heritability = 0.68-0.98). However, causal mutations and functional validation of biological pathways modulating Lp(a) metabolism are lacking. We performed a genome-wide association scan to identify genetic variants associated with Lp(a)-cholesterol levels in the Old Order Amish. We confirmed a previously known locus on chromosome 6q25-26 and found Lp(a) levels also to be significantly associated with a SNP near the APOA5-APOA4-APOC3-APOA1 gene cluster on chromosome 11q23 linked in the Amish to the APOC3 R19X null mutation. On 6q locus, we detected associations of Lp(a)-cholesterol with 118 common variants (P = 5 × 10(-8) to 3.91 × 10(-19)) spanning a â¼5.3 Mb region that included the LPA gene. To further elucidate variation within LPA, we sequenced LPA and identified two variants most strongly associated with Lp(a)-cholesterol, rs3798220 (P = 1.07 × 10(-14)) and rs10455872 (P = 1.85 × 10(-12)). We also measured copy numbers of kringle IV-2 (KIV-2) in LPA using qPCR. KIV-2 numbers were significantly associated with Lp(a)-cholesterol (P = 2.28 × 10(-9)). Conditional analyses revealed that rs3798220 and rs10455872 were associated with Lp(a)-cholesterol levels independent of each other and KIV-2 copy number. Furthermore, we determined for the first time that levels of LPA mRNA were higher in the carriers than non-carriers of rs10455872 (P = 0.0001) and were not different between carriers and non-carriers of rs3798220. Protein levels of apo(a) were higher in the carriers than non-carriers of both rs10455872 and rs3798220. In summary, we identified multiple independent genetic determinants for Lp(a)-cholesterol. These findings provide new insights into Lp(a) regulation.