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1.
medRxiv ; 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38766118

RESUMEN

Background: Despite monogenic and polygenic contributions to cardiovascular disease (CVD), genetic testing is not widely adopted, and current tests are limited by the breadth of surveyed conditions and interpretation burden. Methods: We developed a comprehensive clinical genome CVD test with semi-automated interpretation. Monogenic conditions and risk alleles were selected based on the strength of disease association and evidence for increased disease risk, respectively. Non-CVD secondary findings genes, pharmacogenomic (PGx) variants and CVD polygenic risk scores (PRS) were assessed for inclusion. Test performance was modeled using 2,594 genomes from the 1000 Genomes Project, and further investigated in 20 previously tested individuals. Results: The CVD genome test is composed of a panel of 215 CVD gene-disease pairs, 35 non-CVD secondary findings genes, 4 risk alleles or genotypes, 10 PGx genes and a PRS for coronary artery disease. Modeling of test performance using samples from the 1000 Genomes Project revealed ~6% of individuals with a monogenic finding in a CVD-associated gene, 6% with a risk allele finding, ~1% with a non-CVD secondary finding, and 93% with CVD-associated PGx variants. Assessment of blinded clinical samples showed complete concordance with prior testing. An average of 4 variants were reviewed per case, with interpretation and reporting time ranging from 9-96 min. Conclusions: A genome sequencing based CVD genetic risk assessment can provide comprehensive genetic disease and genetic risk information to patients with CVD. The semi-automated and limited interpretation burden suggest that this testing approach could be scaled to support population-level initiatives.

2.
Vaccines (Basel) ; 11(7)2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37514996

RESUMEN

Vaccination is critical to minimize serious illness and death from COVID-19. Yet uptake of COVID-19 vaccines remains highly variable, particularly among marginalized communities. This article shares lessons learned from four UNICEF interventions that supported Governments to generate acceptance and demand for COVID-19 vaccines in Zambia, Iraq, Ghana, and India. In Zambia, community rapid assessment provided invaluable real-time insights around COVID-19 vaccination and allowed the identification of population segments that share beliefs and motivations regarding COVID-19 vaccination. Findings were subsequently used to develop recommendations tailored to the different personas. In Iraq, a new outreach approach (3iS: Intensification of Integrated Immunization) utilized direct community engagement to deliver health messages and encourage service uptake, resulting in over 4.4 million doses of COVID-19 and routine immunization vaccines delivered in just 8 months. In Ghana, a human-centered design initiative was applied to co-develop community-informed strategies to improve COVID-19 vaccination rates. In India, a risk communication and community engagement initiative reached half a million people over six months, translating into a 25% increase in vaccination rates. These shared approaches can be leveraged to improve COVID-19 vaccination coverage and close gaps in routine immunization across diverse and marginalized communities.

4.
Neurology ; 98(11): 440-445, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35110381

RESUMEN

ATP1A1 encodes the α1 subunit of the sodium-potassium ATPase, an electrogenic cation pump highly expressed in the nervous system. Pathogenic variants in other subunits of the same ATPase, encoded by ATP1A2 or ATP1A3, are associated with syndromes such as hemiplegic migraine, dystonia, or cerebellar ataxia. Worldwide, only 16 families have been reported carrying pathogenic ATP1A1 variants to date. Associated phenotypes are axonal neuropathies, spastic paraplegia, and hypomagnesemia with seizures and intellectual disability. By whole exome or genome sequencing, we identified 5 heterozygous ATP1A1 variants, c.674A>G;p.Gln225Arg, c.1003G>T;p.Gly335Cys, c.1526G>A;p.Gly509Asp, c.2152G>A;p.Gly718Ser, and c.2768T>A;p.Phe923Tyr, in 5 unrelated children with intellectual disability, spasticity, and peripheral, motor predominant neuropathy. Additional features were sensory loss, sleep disturbances, and seizures. All variants occurred de novo and are absent from control populations (MAF GnomAD = 0). Affecting conserved amino acid residues and constrained regions, all variants have high pathogenicity in silico prediction scores. In HEK cells transfected with ouabain-insensitive ATP1A1 constructs, cell viability was significantly decreased in mutants after 72h treatment with the ATPase inhibitor ouabain, demonstrating loss of ATPase function. Replicating the haploinsufficiency mechanism of disease with a gene-specific assay provides pathogenicity information and increases certainty in variant interpretation. This study further expands the genotype-phenotype spectrum of ATP1A1.


Asunto(s)
Discapacidad Intelectual , Migraña con Aura , Humanos , Discapacidad Intelectual/genética , Migraña con Aura/genética , Mutación/genética , Fenotipo , ATPasa Intercambiadora de Sodio-Potasio/genética , Síndrome
5.
Hum Mutat ; 43(6): 765-771, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35181961

RESUMEN

The use of whole-genome sequencing (WGS) has accelerated the pace of gene discovery and highlighted the need for open and collaborative data sharing in the search for novel disease genes and variants. GeneMatcher (GM) is designed to facilitate connections between researchers, clinicians, health-care providers, and others to help in the identification of additional patients with variants in the same candidate disease genes. The Illumina Clinical Services Laboratory offers a WGS test for patients with suspected rare and undiagnosed genetic disease  and regularly submits potential candidate genes to GM to strengthen gene-disease relationships. We describe our experience with GM, including criteria for evaluation of candidate genes, and our workflow for the submission and review process. We have made 69 submissions, 36 of which are currently active. Ten percent of submissions have resulted in publications, with an additional 14 submissions part of ongoing collaborations and expected to result in a publication.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Laboratorios Clínicos , Humanos , Secuenciación Completa del Genoma
6.
Mol Syndromol ; 12(1): 33-40, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33776625

RESUMEN

Tubulinopathies are a group of conditions caused by variants in 6 tubulin genes that present with a spectrum of brain malformations. One of these conditions is TUBB2A-related tubulinopathy. Currently, there are 9 reported individuals with pathogenic variants within the TUBB2A gene, with common manifestations including, but not limited to, global developmental delay, seizures, cortical dysplasia, and dysmorphic corpus callosum. We report 3 patients identified by exome and genome sequencing to have a novel, pathogenic, missense variant in TUBB2A (p.Gly98Arg). They presented similarly with intellectual disability, hypotonia, and global developmental delay and varied with respect to the type of cortical brain malformation, seizure history, diagnosis of autism spectrum disorder, and other features. This case series expands the natural history of TUBB2A-related tubulinopathy while describing the presentation of a novel, pathogenic, missense variant in 3 patients.

7.
Pharmacogenomics J ; 21(2): 251-261, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33462347

RESUMEN

Responsible for the metabolism of ~21% of clinically used drugs, CYP2D6 is a critical component of personalized medicine initiatives. Genotyping CYP2D6 is challenging due to sequence similarity with its pseudogene paralog CYP2D7 and a high number and variety of common structural variants (SVs). Here we describe a novel bioinformatics method, Cyrius, that accurately genotypes CYP2D6 using whole-genome sequencing (WGS) data. We show that Cyrius has superior performance (96.5% concordance with truth genotypes) compared to existing methods (84-86.8%). After implementing the improvements identified from the comparison against the truth data, Cyrius's accuracy has since been improved to 99.3%. Using Cyrius, we built a haplotype frequency database from 2504 ethnically diverse samples and estimate that SV-containing star alleles are more frequent than previously reported. Cyrius will be an important tool to incorporate pharmacogenomics in WGS-based precision medicine initiatives.


Asunto(s)
Citocromo P-450 CYP2D6/genética , Técnicas de Genotipaje/métodos , Alelos , Biología Computacional/métodos , Etnicidad/genética , Genotipo , Haplotipos/genética , Humanos , Polimorfismo Genético/genética , Secuenciación Completa del Genoma/métodos
8.
J Med Genet ; 58(10): 712-716, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-32820033

RESUMEN

OBJECTIVE: To determine the potential disease association between variants in LMBRD2 and complex multisystem neurological and developmental delay phenotypes. METHODS: Here we describe a series of de novo missense variants in LMBRD2 in 10 unrelated individuals with overlapping features. Exome sequencing or genome sequencing was performed on all individuals, and the cohort was assembled through GeneMatcher. RESULTS: LMBRD2 encodes an evolutionary ancient and widely expressed transmembrane protein with no known disease association, although two paralogues are involved in developmental and metabolic disorders. Exome or genome sequencing revealed rare de novo LMBRD2 missense variants in 10 individuals with developmental delay, intellectual disability, thin corpus callosum, microcephaly and seizures. We identified five unique variants and two recurrent variants, c.1448G>A (p.Arg483His) in three cases and c.367T>C (p.Trp123Arg) in two cases. All variants are absent from population allele frequency databases, and most are predicted to be deleterious by multiple in silico damage-prediction algorithms. CONCLUSION: These findings indicate that rare de novo variants in LMBRD2 can lead to a previously unrecognised early-onset neurodevelopmental disorder. Further investigation of individuals harbouring LMBRD2 variants may lead to a better understanding of the function of this ubiquitously expressed gene.


Asunto(s)
Discapacidades del Desarrollo/diagnóstico , Discapacidades del Desarrollo/genética , Trastornos de la Destreza Motora/diagnóstico , Trastornos de la Destreza Motora/genética , Mutación Missense , Malformaciones del Sistema Nervioso/diagnóstico , Malformaciones del Sistema Nervioso/genética , Proteínas de Transporte Nucleocitoplasmático/genética , Alelos , Sustitución de Aminoácidos , Estudios de Cohortes , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Fenotipo
9.
Pediatr Neurol ; 109: 56-62, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32387008

RESUMEN

BACKGROUND: Mutations in the X-linked gene WDR45 cause neurodegeneration with brain iron accumulation type 5. Global developmental delay occurs at an early age with slow progression to dystonia, parkinsonism, and dementia due to progressive iron accumulation in the brain. METHODS: We present 17 new cases and reviewed 106 reported cases of neurodegeneration with brain iron accumulation type 5. Detailed information related to developmental history and key time to event measures was collected. RESULTS: Within this cohort, there were 19 males. Most individuals were molecularly diagnosed by whole-exome testing. Overall 10 novel variants were identified across 11 subjects. All individuals were affected by developmental delay, most prominently in verbal skills. Most individuals experienced a decline in motor and cognitive skills. Although most individuals were affected by seizures, the spectrum ranged from provoked seizures to intractable epilepsy. The imaging findings varied as well, often evolving over time. The classic iron accumulation in the globus pallidus and substantia nigra was noted in half of our cohort and was associated with older age of image acquisition, whereas myelination abnormalities were associated with younger age. CONCLUSIONS: WDR45 mutations lead to a progressive and evolving disorder whose diagnosis is often delayed. Developmental delay and seizures predominate in early childhood, followed by a progressive decline of neurological function. There is variable expressivity in the clinical phenotypes of individuals with WDR45 mutations, suggesting that this gene should be considered in the diagnostic evaluation of children with myelination abnormalities, iron deposition, developmental delay, and epilepsy depending on the age at evaluation.


Asunto(s)
Proteínas Portadoras/genética , Enfermedades Desmielinizantes , Discapacidades del Desarrollo , Epilepsia , Trastornos del Metabolismo del Hierro , Distrofias Neuroaxonales , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Enfermedades Desmielinizantes/diagnóstico , Enfermedades Desmielinizantes/etiología , Enfermedades Desmielinizantes/genética , Enfermedades Desmielinizantes/fisiopatología , Discapacidades del Desarrollo/diagnóstico , Discapacidades del Desarrollo/etiología , Discapacidades del Desarrollo/genética , Discapacidades del Desarrollo/fisiopatología , Epilepsia/diagnóstico , Epilepsia/etiología , Epilepsia/genética , Epilepsia/fisiopatología , Femenino , Humanos , Lactante , Trastornos del Metabolismo del Hierro/complicaciones , Trastornos del Metabolismo del Hierro/diagnóstico , Trastornos del Metabolismo del Hierro/genética , Trastornos del Metabolismo del Hierro/fisiopatología , Masculino , Persona de Mediana Edad , Distrofias Neuroaxonales/complicaciones , Distrofias Neuroaxonales/diagnóstico , Distrofias Neuroaxonales/genética , Distrofias Neuroaxonales/fisiopatología , Fenotipo , Secuenciación del Exoma , Adulto Joven
10.
BMC Public Health ; 19(1): 1039, 2019 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-31375074

RESUMEN

BACKGROUND: Interventions in India to improve menstrual health and hygiene management (MHHM) have been implemented at the national, state, district and school level. However, evaluations of these interventions have been scarce. The objective of the study was to determine if a social and behavioral change communication (SBCC) intervention (GARIMA) had a relationship with knowledge, attitudes, interpersonal communication, restrictions and MHHM using a comparison group post-test only design among 2206 adolescent girls. METHODS: Intervention villages and adolescent girls were selected through stratified random sampling based on where GARIMA was implemented. Villages and adolescent girls in comparison villages were matched socio-demographically to intervention villages and adolescent girls. Multi-level logistic regressions assessed the relationship between the encoded exposure, mediators and MHHM. RESULTS: The results showed that the encoded exposure predicted all behaviors corresponding to MHHM. Additionally, adolescent girls in the high encoded exposure group had significantly higher knowledge about puberty and reproductive parts (AOR: 2.03 (95% CI: 1.31 - 3.15)), positive attitudes towards gender (AOR: 1.48 (95% CI: 1.02 - 2.16)) and higher levels of some discussion and dialogue (AOR: 1.41 (95% CI: 1.04 - 1.92)). CONCLUSIONS: Future programs should use SBCC to improve MHHM behavior but involve families, peers and community members to a greater extent in order to improve attitudes towards menstruation, attitudes towards restrictions, attitudes towards absorbent use and reduce restrictions within the community.


Asunto(s)
Comunicación , Promoción de la Salud/métodos , Higiene/normas , Menstruación/psicología , Cambio Social , Adolescente , Niño , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , India , Evaluación de Programas y Proyectos de Salud , Encuestas y Cuestionarios
11.
Genet Med ; 21(5): 1121-1130, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30293986

RESUMEN

PURPOSE: Current diagnostic testing for genetic disorders involves serial use of specialized assays spanning multiple technologies. In principle, genome sequencing (GS) can detect all genomic pathogenic variant types on a single platform. Here we evaluate copy-number variant (CNV) calling as part of a clinically accredited GS test. METHODS: We performed analytical validation of CNV calling on 17 reference samples, compared the sensitivity of GS-based variants with those from a clinical microarray, and set a bound on precision using orthogonal technologies. We developed a protocol for family-based analysis of GS-based CNV calls, and deployed this across a clinical cohort of 79 rare and undiagnosed cases. RESULTS: We found that CNV calls from GS are at least as sensitive as those from microarrays, while only creating a modest increase in the number of variants interpreted (~10 CNVs per case). We identified clinically significant CNVs in 15% of the first 79 cases analyzed, all of which were confirmed by an orthogonal approach. The pipeline also enabled discovery of a uniparental disomy (UPD) and a 50% mosaic trisomy 14. Directed analysis of select CNVs enabled breakpoint level resolution of genomic rearrangements and phasing of de novo CNVs. CONCLUSION: Robust identification of CNVs by GS is possible within a clinical testing environment.


Asunto(s)
Variaciones en el Número de Copia de ADN/genética , Enfermedades Raras/genética , Enfermedades no Diagnosticadas/genética , Adolescente , Niño , Preescolar , Mapeo Cromosómico/métodos , Estudios de Cohortes , Femenino , Pruebas Genéticas/métodos , Genoma Humano , Genómica/métodos , Humanos , Lactante , Masculino , Enfermedades Raras/diagnóstico , Enfermedades no Diagnosticadas/diagnóstico , Secuenciación Completa del Genoma/métodos , Adulto Joven
12.
Front Pharmacol ; 9: 305, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29674966

RESUMEN

The CYP2D6 gene encodes an enzyme important in the metabolism of many commonly used medications. Variation in CYP2D6 is associated with inter-individual differences in medication response, and genetic testing is used to optimize medication therapy. This report describes a retrospective study of CYP2D6 allele frequencies in a large population of 104,509 de-identified patient samples across all regions of the United States (US). Thirty-seven unique CYP2D6 alleles including structural variants were identified. A majority of these alleles had frequencies which matched published frequency data from smaller studies, while eight had no previously published frequencies. Importantly, CYP2D6 structural variants were observed in 13.1% of individuals and accounted for 7% of the total variants observed. The majority of structural variants detected (73%) were decreased-function or no-function alleles. As such, structural variants were found in approximately one-third (30%) of CYP2D6 poor metabolizers in this study. This is the first CYP2D6 study to evaluate, with a consistent methodology, both structural variants and single copy alleles in a large US population, and the results suggest that structural variants have a substantial impact on CYP2D6 function.

13.
Hum Mutat ; 39(2): 281-291, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29193635

RESUMEN

We report five individuals with loss-of-function of the X-linked AMMECR1: a girl with a balanced X-autosome translocation and inactivation of the normal X-chromosome; two boys with maternally inherited and de novo nonsense variants; and two half-brothers with maternally inherited microdeletion variants. They present with short stature, cardiac and skeletal abnormalities, and hearing loss. Variants of unknown significance in AMMECR1 in four male patients from two families with partially overlapping phenotypes were previously reported. AMMECR1 is coexpressed with genes implicated in cell cycle regulation, five of which were previously associated with growth and bone alterations. Our knockdown of the zebrafish orthologous gene resulted in phenotypes reminiscent of patients' features. The increased transcript and encoded protein levels of AMMECR1L, an AMMECR1 paralog, in the t(X;9) patient's cells indicate a possible partial compensatory mechanism. AMMECR1 and AMMECR1L proteins dimerize and localize to the nucleus as suggested by their nucleic acid-binding RAGNYA folds. Our results suggest that AMMECR1 is potentially involved in cell cycle control and linked to a new syndrome with growth, bone, heart, and kidney alterations with or without elliptocytosis.


Asunto(s)
Huesos/fisiología , Corazón/fisiología , Proteínas/genética , Animales , Western Blotting , Huesos/metabolismo , Ciclo Celular/genética , Ciclo Celular/fisiología , Línea Celular , Exoma/genética , Femenino , Células HeLa , Humanos , Masculino , Secuenciación Completa del Genoma , Pez Cebra
14.
Circ Cardiovasc Genet ; 10(6)2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29237685

RESUMEN

BACKGROUND: Identity-by-descent mapping using empirical estimates of identity-by-descent allele sharing may be useful for studies of complex traits in founder populations, where hidden relationships may augment the inherent genetic information that can be used for localization. METHODS AND RESULTS: Through identity-by-descent mapping, using ≈400 000 single-nucleotide polymorphisms (SNPs), of serum lipid profiles, we identified a major linkage signal for triglycerides in 1007 Pima Indians (LOD=9.23; P=3.5×10-11 on chromosome 11q). In subsequent fine-mapping and replication association studies in ≈7500 Amerindians, we determined that this signal reflects effects of a loss-of-function Ala43Thr substitution in APOC3 (rs147210663) and 3 established functional SNPs in APOA5. The association with rs147210663 was particularly strong; each copy of the Thr allele conferred 42% lower triglycerides (ß=-0.92±0.059 SD unit; P=9.6×10-55 in 4668 Pimas and 2793 Southwest Amerindians combined). The Thr allele is extremely rare in most global populations but has a frequency of 2.5% in Pimas. We further demonstrated that 3 APOA5 SNPs with established functional impact could explain the association with the most well-replicated SNP (rs964184) for triglycerides identified by genome-wide association studies. Collectively, these 4 SNPs account for 6.9% of variation in triglycerides in Pimas (and 4.1% in Southwest Amerindians), and their inclusion in the original linkage model reduced the linkage signal to virtually null. CONCLUSIONS: APOC3/APOA5 constitutes a major locus for serum triglycerides in Amerindians, especially the Pimas, and these results provide an empirical example for the concept that population-based linkage analysis is a useful strategy to identify complex trait variants.


Asunto(s)
Apolipoproteína C-III/genética , Efecto Fundador , Estudio de Asociación del Genoma Completo , Indígenas Norteamericanos/genética , Mutación , Triglicéridos/sangre , Apolipoproteína A-V/genética , Cromosomas Humanos Par 11/genética , Frecuencia de los Genes , Genotipo , Haplotipos , Humanos , Desequilibrio de Ligamiento , Lípidos/sangre , Polimorfismo de Nucleótido Simple
15.
J Health Commun ; 22(1): 66-74, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28060582

RESUMEN

Entertainment-education is an effective health communication strategy that combines or embeds educational messages into entertainment programs to bring about social and behavior change. For years, scholars have considered how entertainment-education works. Some contemporary theories posit that entertainment-education does not engender behavior change directly but does so through mediating variables. This study adds to the literature on this topic by exploring the direct relationship between exposure and social norms instead of their relationship through behavior as a mediator. Novel to this study is the use of encoded exposure, a continuous and recognition-based measure of exposure that includes ever watching, recall, involvement, and dose in its operationalization. Using cross-sectional data from Kyunki … Jeena Issi Ka Naam Hai, an entertainment-education program in India, this exploratory analysis indicates a positive and significant relationship between encoded exposure and social norms. How can this finding be applied to future programs? Questions remain, and replication is needed, but if it is not essential to go through behavior in order to change social norms, then implications emerge for the theory and practice of entertainment-education.


Asunto(s)
Comunicación en Salud/métodos , Educación en Salud/métodos , Normas Sociales , Televisión/estadística & datos numéricos , Estudios Transversales , Femenino , Humanos , India , Encuestas y Cuestionarios
16.
PLoS Genet ; 11(8): e1005352, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26305897

RESUMEN

Diabetic kidney disease (DKD) is the most common etiology of chronic kidney disease (CKD) in the industrialized world and accounts for much of the excess mortality in patients with diabetes mellitus. Approximately 45% of U.S. patients with incident end-stage kidney disease (ESKD) have DKD. Independent of glycemic control, DKD aggregates in families and has higher incidence rates in African, Mexican, and American Indian ancestral groups relative to European populations. The Family Investigation of Nephropathy and Diabetes (FIND) performed a genome-wide association study (GWAS) contrasting 6,197 unrelated individuals with advanced DKD with healthy and diabetic individuals lacking nephropathy of European American, African American, Mexican American, or American Indian ancestry. A large-scale replication and trans-ethnic meta-analysis included 7,539 additional European American, African American and American Indian DKD cases and non-nephropathy controls. Within ethnic group meta-analysis of discovery GWAS and replication set results identified genome-wide significant evidence for association between DKD and rs12523822 on chromosome 6q25.2 in American Indians (P = 5.74x10-9). The strongest signal of association in the trans-ethnic meta-analysis was with a SNP in strong linkage disequilibrium with rs12523822 (rs955333; P = 1.31x10-8), with directionally consistent results across ethnic groups. These 6q25.2 SNPs are located between the SCAF8 and CNKSR3 genes, a region with DKD relevant changes in gene expression and an eQTL with IPCEF1, a gene co-translated with CNKSR3. Several other SNPs demonstrated suggestive evidence of association with DKD, within and across populations. These data identify a novel DKD susceptibility locus with consistent directions of effect across diverse ancestral groups and provide insight into the genetic architecture of DKD.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Nefropatías Diabéticas/genética , Negro o Afroamericano/genética , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/etnología , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Hispánicos o Latinos/genética , Humanos , Indígenas Norteamericanos/genética , Proteínas de Unión al ARN/genética , Estados Unidos , Población Blanca/genética
18.
PLoS One ; 9(7): e102544, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25014012

RESUMEN

BACKGROUND: Genotype imputation is commonly used in genetic association studies to test untyped variants using information on linkage disequilibrium (LD) with typed markers. Imputing genotypes requires a suitable reference population in which the LD pattern is known, most often one selected from HapMap. However, some populations, such as American Indians, are not represented in HapMap. In the present study, we assessed accuracy of imputation using HapMap reference populations in a genome-wide association study in Pima Indians. RESULTS: Data from six randomly selected chromosomes were used. Genotypes in the study population were masked (either 1% or 20% of SNPs available for a given chromosome). The masked genotypes were then imputed using the software Markov Chain Haplotyping Algorithm. Using four HapMap reference populations, average genotype error rates ranged from 7.86% for Mexican Americans to 22.30% for Yoruba. In contrast, use of the original Pima Indian data as a reference resulted in an average error rate of 1.73%. CONCLUSIONS: Our results suggest that the use of HapMap reference populations results in substantial inaccuracy in the imputation of genotypes in American Indians. A possible solution would be to densely genotype or sequence a reference American Indian population.


Asunto(s)
Genoma Humano , Genotipo , Indígenas Norteamericanos , Polimorfismo de Nucleótido Simple , Programas Informáticos , Algoritmos , Mapeo Cromosómico , Frecuencia de los Genes , Estudio de Asociación del Genoma Completo , Proyecto Mapa de Haplotipos , Humanos , Desequilibrio de Ligamiento , Estados Unidos
19.
Hum Mol Genet ; 22(21): 4438-49, 2013 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-23825110

RESUMEN

To identify genes that affect body mass index (BMI) in American Indians who are predominately of Pima Indian heritage, we previously completed a genome-wide association study in 1120 American Indians. That study also included follow-up genotyping for 9 SNPs in 2133 additional subjects. A comprehensive follow-up study has subsequently been completed where 292 SNPs were genotyped in 3562 subjects, of which 128 SNPs were assessed for replication in 3238 additional subjects. In the combined subjects (n = 6800), BMI associations for two SNPs, rs12882548 and rs11652094, approached genome-wide significance (P = 6.7 × 10(-7) and 8.1 × 10(-7), respectively). Rs12882548 is located in a gene desert on chromosome 14 and rs11652094 maps near MAP2K3. Several SNPs in the MAP2K3 region including rs11652094 were also associated with BMI in Caucasians from the GIANT consortium (P = 10(-2)-10(-5)), and the combined P-values across both American Indians and Caucasian were P = 10(-4)-10(-9). Follow-up sequencing across MAP2K3 identified several paralogous sequence variants indicating that the region may have been duplicated. MAP2K3 expression levels in adipose tissue biopsies were positively correlated with BMI, although it is unclear if this correlation is a cause or effect. In vitro studies with cloned MAP2K3 promoters suggest that MAP2K3 expression may be up-regulated during adipogenesis. Microarray analyses of mouse hypothalamus cells expressing constitutively active MAP2K3 identified several up-regulated genes involved in immune/inflammatory pathways and a gene, Hap1, thought to play a role in appetite regulation. We conclude that MAP2K3 is a reproducible obesity locus that may affect body weight via complex mechanisms involving appetite regulation and hypothalamic inflammation.


Asunto(s)
Índice de Masa Corporal , Hipotálamo/metabolismo , Inflamación/genética , MAP Quinasa Quinasa 3/genética , MAP Quinasa Quinasa 3/metabolismo , Células 3T3-L1 , Adipocitos/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Peso Corporal , Línea Celular , Niño , Preescolar , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Hipotálamo/citología , Hipotálamo/embriología , Indígenas Norteamericanos/genética , Estudios Longitudinales , Ratones , Persona de Mediana Edad , Obesidad/genética , Polimorfismo de Nucleótido Simple , Población Blanca/genética , Adulto Joven
20.
Obesity (Silver Spring) ; 21(1): 193-202, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23505186

RESUMEN

OBJECTIVE: A genome-wide association study (GWAS) was recently completed in 1120 Pima Indians to identify loci that influence BMI. Among the top 100 signals were three variants that mapped within the lysophosphatidylglycerol acyltransferase 1 (LPGAT1) gene. LPGAT1 belongs to a large family of acyltransferases, which are involved in a variety of biological processes including pathways that regulate energy homeostasis and body weight. Therefore LPGAT1 was analyzed as a candidate gene for obesity in Pima Indians. DESIGN AND METHODS: Variants (n = 26) located within and adjacent to LPGAT1 including a novel 27bp deletion in the 5'-untranslated region identified by sequencing were genotyped in a population-based sample of 3,391 full-heritage Pima Indians living in the Gila River Indian Community. Replication of selected variants was assessed in a second sample of 3,327 mixed-heritage Native Americans from the same community. RESULTS: Variants with nominal associations with BMI in each of the two independent samples (tagged by rs112662024 and rs12058008) had associations of P = 1-4 × 10(-5) in the combined sample (n = 6718). A haplotype that includes the novel 27bp deletion, which does not occur in Caucasians, showed the strongest association with BMI in the full-heritage Pima Indians. In vitro functional studies provided suggestive evidence that this 27bp deletion may affect transcriptional or posttranscriptional regulation. Analysis of LPGAT1 cDNA from human preadipocytes identified an additional exon whose sequence could potentially serve as a mitochondrial targeting peptide. CONCLUSIONS: LPGAT1 is a novel gene that influences BMI in Native Americans.


Asunto(s)
Aciltransferasas/genética , Tejido Adiposo , Índice de Masa Corporal , Indígenas Norteamericanos/genética , Obesidad/genética , Polimorfismo de Nucleótido Simple , Eliminación de Secuencia , Composición Corporal/genética , Peso Corporal , ADN Complementario , Metabolismo Energético , Exones , Regulación de la Expresión Génica , Variación Genética , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Intrones , Mitocondrias , Obesidad/etnología , Péptidos/genética , Transducción de Señal
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