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1.
Sci Rep ; 11(1): 6659, 2021 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-33758277

RESUMEN

Human Y chromosome haplogroup J1-M267 is a common male lineage in West Asia. One high-frequency region-encompassing the Arabian Peninsula, southern Mesopotamia, and the southern Levant-resides ~ 2000 km away from the other one found in the Caucasus. The region between them, although has a lower frequency, nevertheless demonstrates high genetic diversity. Studies associate this haplogroup with the spread of farming from the Fertile Crescent to Europe, the spread of mobile pastoralism in the desert regions of the Arabian Peninsula, the history of the Jews, and the spread of Islam. Here, we study past human male demography in West Asia with 172 high-coverage whole Y chromosome sequences and 889 genotyped samples of haplogroup J1-M267. We show that this haplogroup evolved ~ 20,000 years ago somewhere in northwestern Iran, the Caucasus, the Armenian Highland, and northern Mesopotamia. The major branch-J1a1a1-P58-evolved during the early Holocene ~ 9500 years ago somewhere in the Arabian Peninsula, the Levant, and southern Mesopotamia. Haplogroup J1-M267 expanded during the Chalcolithic, the Bronze Age, and the Iron Age. Most probably, the spread of Afro-Asiatic languages, the spread of mobile pastoralism in the arid zones, or both of these events together explain the distribution of haplogroup J1-M267 we see today in the southern regions of West Asia.


Asunto(s)
Alelos , Cromosomas Humanos Y , Haplotipos , Teorema de Bayes , Evolución Molecular , Genética de Población , Humanos , Filogenia , Polimorfismo de Nucleótido Simple , Análisis Espacio-Temporal
2.
Mol Biol Evol ; 36(2): 315-327, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30428071

RESUMEN

The indigenous inhabitants of Siberia live in some of the harshest environments on earth, experiencing extended periods of severe cold temperatures, dramatic variation in photoperiod, and limited and highly variable food resources. While the successful long-term settlement of this area by humans required multiple behavioral and cultural innovations, the nature of the underlying genetic changes has generally remained elusive. In this study, we used a three-part approach to identify putative targets of positive natural selection in Siberians. We first performed selection scans on whole exome and genome-wide single nucleotide polymorphism array data from multiple Siberian populations. We then annotated candidates in the tails of the empirical distributions, focusing on candidates with evidence linking them to biological processes and phenotypes previously identified as relevant to adaptation in circumpolar groups. The top candidates were then genotyped in additional populations to determine their spatial allele frequency distributions and associations with climate variables. Our analysis reveals missense mutations in three genes involved in lipid metabolism (PLA2G2A, PLIN1, and ANGPTL8) that exhibit genomic and spatial patterns consistent with selection for cold climate and/or diet. These variants are unified by their connection to brown adipose tissue and may help to explain previously observed physiological differences in Siberians such as low serum lipid levels and increased basal metabolic rate. These results support the hypothesis that indigenous Siberians have genetically adapted to their local environment by selection on multiple genes.


Asunto(s)
Adaptación Biológica , Evolución Molecular , Genoma Humano , Selección Genética , Proteína 8 Similar a la Angiopoyetina , Proteínas Similares a la Angiopoyetina/genética , Clima , Dieta , Frecuencia de los Genes , Fosfolipasas A2 Grupo II/genética , Haplotipos , Humanos , Desequilibrio de Ligamiento , Mutación Missense , Hormonas Peptídicas/genética , Perilipina-1/genética , Polimorfismo de Nucleótido Simple , Siberia
3.
Am J Hum Biol ; 30(6): e23194, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30408262

RESUMEN

OBJECTIVES: We examined autosomal genome-wide SNPs and Y-chromosome data from 15 Siberian and 12 reference populations to study the affinities of Siberian populations, and to address hypotheses about the origin of the Samoyed peoples. METHODS: Samples were genotyped for 567 096 autosomal SNPs and 147 Y-chromosome polymorphic sites. For several analyses, we used 281 093 SNPs from the intersection of our data with publicly available ancient Siberian samples. To examine genetic relatedness among populations, we applied PCA, FST , TreeMix, and ADMIXTURE analyses. To explore the potential effect of demography and evolutionary processes, the distribution of ROH and IBD sharing within population were studied. RESULTS: Analyses of autosomal and Y-chromosome data reveal high differentiation of the Siberian groups. The Siberian populations have a large proportion of their genome in ROH and IBD segments. Several populations (ie, Nganasans, Evenks, Yukagirs, and Koryaks) do not appear to have experienced admixture with other Siberian populations (ie, producing only positive f3), while for the other tested populations the composition of mixing sources always included Nganasans or Evenks. The Nganasans from the Taymyr Peninsula demonstrate the greatest level of shared shorter ROH and IBD with nearly all other Siberian populations. CONCLUSIONS: Autosomal SNP and Y-chromosome data demonstrate that Samoyedic populations differ significantly in their genetic composition. Genetic relationship is observed only between Forest and Tundra Nentsi. Selkups are affiliated with the Kets from the Yenisey River, while the Nganasans are separated from their linguistic neighbors, showing closer affinities with the Evenks and Yukagirs.


Asunto(s)
Variación Genética , Lingüística , Polimorfismo de Nucleótido Simple , Cromosomas Humanos Y/genética , ADN Antiguo/análisis , Migración Humana , Humanos , Siberia
4.
Mol Biol Evol ; 34(10): 2439-2452, 2017 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-28957506

RESUMEN

Indonesia, an island nation as large as continental Europe, hosts a sizeable proportion of global human diversity, yet remains surprisingly undercharacterized genetically. Here, we substantially expand on existing studies by reporting genome-scale data for nearly 500 individuals from 25 populations in Island Southeast Asia, New Guinea, and Oceania, notably including previously unsampled islands across the Indonesian archipelago. We use high-resolution analyses of haplotype diversity to reveal fine detail of regional admixture patterns, with a particular focus on the Holocene. We find that recent population history within Indonesia is complex, and that populations from the Philippines made important genetic contributions in the early phases of the Austronesian expansion. Different, but interrelated processes, acted in the east and west. The Austronesian migration took several centuries to spread across the eastern part of the archipelago, where genetic admixture postdates the archeological signal. As with the Neolithic expansion further east in Oceania and in Europe, genetic mixing with local inhabitants in eastern Indonesia lagged behind the arrival of farming populations. In contrast, western Indonesia has a more complicated admixture history shaped by interactions with mainland Asian and Austronesian newcomers, which for some populations occurred more than once. Another layer of complexity in the west was introduced by genetic contact with South Asia and strong demographic events in isolated local groups.


Asunto(s)
Pueblo Asiatico/genética , Variación Genética/genética , Genoma Humano/genética , Asia/etnología , Asia Sudoriental/etnología , ADN Mitocondrial/genética , Evolución Molecular , Asia Oriental , Genética de Población/métodos , Haplotipos , Migración Humana , Humanos , Indonesia/etnología , Islas , Oceanía/etnología
5.
Mol Biol Evol ; 34(11): 2913-2926, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28962010

RESUMEN

Siberia is one of the coldest environments on Earth and has great seasonal temperature variation. Long-term settlement in northern Siberia undoubtedly required biological adaptation to severe cold stress, dramatic variation in photoperiod, and limited food resources. In addition, recent archeological studies show that humans first occupied Siberia at least 45,000 years ago; yet our understanding of the demographic history of modern indigenous Siberians remains incomplete. In this study, we use whole-exome sequencing data from the Nganasans and Yakuts to infer the evolutionary history of these two indigenous Siberian populations. Recognizing the complexity of the adaptive process, we designed a model-based test to systematically search for signatures of polygenic selection. Our approach accounts for stochasticity in the demographic process and the hitchhiking effect of classic selective sweeps, as well as potential biases resulting from recombination rate and mutation rate heterogeneity. Our demographic inference shows that the Nganasans and Yakuts diverged ∼12,000-13,000 years ago from East-Asian ancestors in a process involving continuous gene flow. Our polygenic selection scan identifies seven candidate gene sets with Siberian-specific signals. Three of these gene sets are related to diet, especially to fat metabolism, consistent with the hypothesis of adaptation to a fat-rich animal diet. Additional testing rejects the effect of hitchhiking and favors a model in which selection yields small allele frequency changes at multiple unlinked genes.


Asunto(s)
Aclimatación/genética , Adaptación Biológica/genética , Alelos , Pueblo Asiatico/genética , Evolución Biológica , ADN Mitocondrial/genética , Demografía/métodos , Dieta , Grasas de la Dieta , Etnicidad/genética , Exoma/genética , Flujo Génico/genética , Frecuencia de los Genes/genética , Variación Genética/genética , Genética de Población/métodos , Humanos , Herencia Multifactorial/genética , Filogenia , Siberia , Secuenciación del Exoma/métodos
6.
Mol Biol Evol ; 33(9): 2273-84, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27274003

RESUMEN

At least since the Neolithic, humans have largely lived in networks of small, traditional communities. Often socially isolated, these groups evolved distinct languages and cultures over microgeographic scales of just tens of kilometers. Population genetic theory tells us that genetic drift should act quickly in such isolated groups, thus raising the question: do networks of small human communities maintain levels of genetic diversity over microgeographic scales? This question can no longer be asked in most parts of the world, which have been heavily impacted by historical events that make traditional society structures the exception. However, such studies remain possible in parts of Island Southeast Asia and Oceania, where traditional ways of life are still practiced. We captured genome-wide genetic data, together with linguistic records, for a case-study system-eight villages distributed across Sumba, a small, remote island in eastern Indonesia. More than 4,000 years after these communities were established during the Neolithic period, most speak different languages and can be distinguished genetically. Yet their nuclear diversity is not reduced, instead being comparable to other, even much larger, regional groups. Modeling reveals a separation of time scales: while languages and culture can evolve quickly, creating social barriers, sporadic migration averaged over many generations is sufficient to keep villages linked genetically. This loosely-connected network structure, once the global norm and still extant on Sumba today, provides a living proxy to explore fine-scale genome dynamics in the sort of small traditional communities within which the most recent episodes of human evolution occurred.


Asunto(s)
Etnicidad/genética , Variación Genética , Nativos de Hawái y Otras Islas del Pacífico/genética , Asia Sudoriental , Evolución Biológica , Estudios de Asociación Genética , Genética de Población , Genómica , Geografía , Humanos , Indonesia , Lenguaje , Lingüística , Polimorfismo de Nucleótido Simple , Dinámica Poblacional
7.
PLoS One ; 11(4): e0153841, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27082237

RESUMEN

Hearing loss (HL) is one of the most common sensorineural disorders and several dozen genes contribute to its pathogenesis. Establishing a genetic diagnosis of HL is of great importance for clinical evaluation of deaf patients and for estimating recurrence risks for their families. Efforts to identify genes responsible for HL have been challenged by high genetic heterogeneity and different ethnic-specific prevalence of inherited deafness. Here we present the utility of whole exome sequencing (WES) for identifying candidate causal variants for previously unexplained nonsyndromic HL of seven patients from four unrelated Altaian families (the Altai Republic, South Siberia). The WES analysis revealed homozygous missense mutations in three genes associated with HL. Mutation c.2168A>G (SLC26A4) was found in one family, a novel mutation c.1111G>C (OTOF) was revealed in another family, and mutation c.5254G>A (RAI1) was found in two families. Sanger sequencing was applied for screening of identified variants in an ethnically diverse cohort of other patients with HL (n = 116) and in Altaian controls (n = 120). Identified variants were found only in patients of Altaian ethnicity (n = 93). Several lines of evidences support the association of homozygosity for discovered variants c.5254G>A (RAI1), c.1111C>G (OTOF), and c.2168A>G (SLC26A4) with HL in Altaian patients. Local prevalence of identified variants implies possible founder effect in significant number of HL cases in indigenous population of the Altai region. Notably, this is the first reported instance of patients with RAI1 missense mutation whose HL is not accompanied by specific traits typical for Smith-Magenis syndrome. Presumed association of RAI1 gene variant c.5254G>A with isolated HL needs to be proved by further experimental studies.


Asunto(s)
Sordera/genética , Exoma , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana/genética , Factores de Transcripción/genética , Estudios de Cohortes , Análisis Mutacional de ADN , Exones , Salud de la Familia , Femenino , Variación Genética , Genoma Humano , Geografía , Homocigoto , Humanos , Masculino , Mutación , Mutación Missense , Linaje , Siberia , Transportadores de Sulfato , Transactivadores
8.
J Hum Genet ; 61(3): 181-91, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26607180

RESUMEN

As a result of the combination of great linguistic and cultural diversity, the highland populations of Daghestan present an excellent opportunity to test the hypothesis of language-gene coevolution at a fine geographic scale. However, previous genetic studies generally have been restricted to uniparental markers and have not included many of the key populations of the region. To improve our understanding of the genetic structure of Daghestani populations and to investigate possible correlations between genetic and linguistic variation, we analyzed ~550,000 autosomal single nucleotide polymorphisms, phylogenetically informative Y chromosome markers and mtDNA haplotypes in 21 ethnic Daghestani groups. We found high levels of population structure in Daghestan consistent with the hypothesis of long-term isolation among populations of the highland Caucasus. Highland Daghestani populations exhibit extremely high levels of between-population diversity for all genetic systems tested, leading to some of the highest FST values observed for any region of the world. In addition, we find a significant positive correlation between gene and language diversity, suggesting that these two aspects of human diversity have coevolved as a result of historical patterns of social interaction among highland farmers at the community level. Finally, our data are consistent with the hypothesis that most Daghestanian-speaking groups descend from a common ancestral population (~6000-6500 years ago) that spread to the Caucasus by demic diffusion followed by population fragmentation and low levels of gene flow.


Asunto(s)
Evolución Molecular , Genética de Población , Lingüística , Cromosomas Humanos Y , ADN Mitocondrial/genética , Daguestán , Marcadores Genéticos , Haplotipos , Humanos , Filogenia , Polimorfismo de Nucleótido Simple , Análisis de Componente Principal
9.
Mol Biol Evol ; 32(9): 2254-62, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25968961

RESUMEN

Marriage rules, the community prescriptions that dictate who an individual can or cannot marry, are extremely diverse and universally present in traditional societies. A major focus of research in the early decades of modern anthropology, marriage rules impose social and economic forces that help structure societies and forge connections between them. However, in those early anthropological studies, the biological benefits or disadvantages of marriage rules could not be determined. We revisit this question by applying a novel simulation framework and genome-wide data to explore the effects of Asymmetric Prescriptive Alliance, an elaborate set of marriage rules that has been a focus of research for many anthropologists. Simulations show that strict adherence to these marriage rules reduces genetic diversity on the autosomes, X chromosome and mitochondrial DNA, but relaxed compliance produces genetic diversity similar to random mating. Genome-wide data from the Indonesian community of Rindi, one of the early study populations for Asymmetric Prescriptive Alliance, are more consistent with relaxed compliance than strict adherence. We therefore suggest that, in practice, marriage rules are treated with sufficient flexibility to allow social connectivity without significant degradation of biological diversity.


Asunto(s)
Variación Genética , Matrimonio , Cultura , Femenino , Humanos , Masculino , Modelos Genéticos
10.
Genetics ; 200(2): 469-81, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25852078

RESUMEN

Admixture between long-separated populations is a defining feature of the genomes of many species. The mosaic block structure of admixed genomes can provide information about past contact events, including the time and extent of admixture. Here, we describe an improved wavelet-based technique that better characterizes ancestry block structure from observed genomic patterns. principal components analysis is first applied to genomic data to identify the primary population structure, followed by wavelet decomposition to develop a new characterization of local ancestry information along the chromosomes. For testing purposes, this method is applied to human genome-wide genotype data from Indonesia, as well as virtual genetic data generated using genome-scale sequential coalescent simulations under a wide range of admixture scenarios. Time of admixture is inferred using an approximate Bayesian computation framework, providing robust estimates of both admixture times and their associated levels of uncertainty. Crucially, we demonstrate that this revised wavelet approach, which we have released as the R package adwave, provides improved statistical power over existing wavelet-based techniques and can be used to address a broad range of admixture questions.


Asunto(s)
Genética de Población , Genómica , Modelos Genéticos , Análisis de Ondículas , Algoritmos , Estudio de Asociación del Genoma Completo , Genómica/métodos , Humanos , Indonesia , Polimorfismo de Nucleótido Simple , Análisis de Componente Principal
11.
Eur J Hum Genet ; 23(10): 1405-12, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25604856

RESUMEN

Isolated populations are valuable resources for mapping disease genes, as inbreeding increases genome-wide homozygosity and enhances the ability to map disease alleles on a genetically uniform background within a relatively homogenous environment. The populations of Daghestan are thought to have resided in the Caucasus Mountains for hundreds of generations and are characterized by a high prevalence of certain complex diseases. To explore the extent to which their unique population history led to increased levels of inbreeding, we genotyped >550 000 autosomal single-nucleotide polymorphisms (SNPs) in a set of 14 population isolates speaking Nakh-Daghestanian (ND) languages. The ND-speaking populations showed greatly elevated coefficients of inbreeding, very high numbers and long lengths of Runs of Homozygosity, and elevated linkage disequilibrium compared with surrounding groups from the Caucasus, the Near East, Europe, Central and South Asia. These results are consistent with the hypothesis that most ND-speaking groups descend from a common ancestral population that fragmented into a series of genetic isolates in the Daghestanian highlands. They have subsequently maintained a long-term small effective population size as a result of constant inbreeding and very low levels of gene flow. Given these findings, Daghestanian population isolates are likely to be useful for mapping genes associated with complex diseases.


Asunto(s)
Genoma Humano/genética , Polimorfismo de Nucleótido Simple/genética , Asia , Mapeo Cromosómico/métodos , Consanguinidad , Europa (Continente) , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Homocigoto , Humanos , Endogamia/métodos , Desequilibrio de Ligamiento/genética , Medio Oriente
13.
Eur J Hum Genet ; 23(3): 369-73, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24896152

RESUMEN

The highly structured distribution of Y-chromosome haplogroups suggests that current patterns of variation may be informative of past population processes. However, limited phylogenetic resolution, particularly of subclades within haplogroup K, has obscured the relationships of lineages that are common across Eurasia. Here we genotype 13 new highly informative single-nucleotide polymorphisms in a worldwide sample of 4413 males that carry the derived allele at M526, and reconstruct an NRY haplogroup tree with significantly higher resolution for the major clade within haplogroup K, K-M526. Although K-M526 was previously characterized by a single polytomy of eight major branches, the phylogenetic structure of haplogroup K-M526 is now resolved into four major subclades (K2a-d). The largest of these subclades, K2b, is divided into two clusters: K2b1 and K2b2. K2b1 combines the previously known haplogroups M, S, K-P60 and K-P79, whereas K2b2 comprises haplogroups P and its subhaplogroups Q and R. Interestingly, the monophyletic group formed by haplogroups R and Q, which make up the majority of paternal lineages in Europe, Central Asia and the Americas, represents the only subclade with K2b that is not geographically restricted to Southeast Asia and Oceania. Estimates of the interval times for the branching events between M9 and P295 point to an initial rapid diversification process of K-M526 that likely occurred in Southeast Asia, with subsequent westward expansions of the ancestors of haplogroups R and Q.


Asunto(s)
Cromosomas Humanos Y , Variación Genética , Genética de Población , Haplotipos , Filogenia , Asia Sudoriental , Etnicidad/genética , Frecuencia de los Genes , Humanos , Masculino , Mutación , Filogeografía , Polimorfismo Genético
14.
Investig Genet ; 5(1): 15, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25452838

RESUMEN

BACKGROUND: The peopling of Europe and the nature of the Neolithic agricultural migration as a primary issue in the modern human colonization of the globe is still widely debated. At present, much uncertainty is associated with the reconstruction of the routes of migration for the first farmers from the Near East. In this context, hospitable climatic conditions and the key geographic position of the Armenian Highland suggest that it may have served as a conduit for several waves of expansion of the first agriculturalists from the Near East to Europe and the North Caucasus. RESULTS: Here, we assess Y-chromosomal distribution in six geographically distinct populations of Armenians that roughly represent the extent of historical Armenia. Using the general haplogroup structure and the specific lineages representing putative genetic markers of the Neolithic Revolution, haplogroups R1b1a2, J2, and G, we identify distinct patterns of genetic affinity between the populations of the Armenian Highland and the neighboring ones north and west from this area. CONCLUSIONS: Based on the results obtained, we suggest a new insight on the different routes and waves of Neolithic expansion of the first farmers through the Armenian Highland. We detected at least two principle migratory directions: (1) westward alongside the coastline of the Mediterranean Sea and (2) northward to the North Caucasus.

15.
J Hum Genet ; 59(9): 494-503, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25078354

RESUMEN

Timor, an eastern Indonesian island linking mainland Asia with Australia and the Pacific world, had a complex history, including its role as a contact zone between two language families (Austronesian and Trans-New Guinean), as well as preserving elements of a rich Austronesian cultural heritage, such as matrilocal marriage practices. Using an array of biparental (autosomal and X-chromosome single-nucleotide polymorphisms) and uniparental markers (Y chromosome and mitochondrial DNA), we reconstruct a broad genetic profile of Timorese in the Belu regency of West Timor, including the traditional princedom of Wehali, focusing on the effects of cultural practices, such as language and social change, on patterns of genetic diversity. Sex-linked data highlight the different histories and social pressures experienced by women and men. Measures of diversity and population structure show that Timorese men had greater local mobility than women, as expected in matrilocal communities, where women remain in their natal village, whereas men move to the home village of their wife. Reaching further back in time, maternal loci (mitochondrial DNA and the X chromosome) are dominated by lineages with immigrant Asian origins, whereas paternal loci (Y chromosome) tend to exhibit lineages of the earliest settlers in the eastern Indonesian region. The dominance of Asian female lineages is especially apparent in the X chromosome compared with the autosomes, suggesting that women played a paramount role during and after the period of Asian immigration into Timor, perhaps driven by the matrilocal marriage practices of expanding Austronesian communities.


Asunto(s)
ADN Mitocondrial/genética , Variación Genética , Genética de Población/tendencias , Conducta Social , Análisis de Varianza , Cromosomas Humanos X/genética , Cromosomas Humanos Y/genética , Diversidad Cultural , Femenino , Frecuencia de los Genes , Genética de Población/métodos , Geografía , Haplotipos , Humanos , Indonesia , Lenguaje , Masculino , Datos de Secuencia Molecular , Crecimiento Demográfico , Análisis de Secuencia de ADN , Aislamiento Social
16.
Eur J Hum Genet ; 22(1): 94-8, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23632791

RESUMEN

J-wave syndromes have been associated with increased risk of ventricular fibrillation and sudden cardiac death. Previous studies have identified the KCNJ8-S422L variant in heterozygous form in individuals with J-wave syndromes. Its absence in over 1500 controls, coupled with in vitro analysis, have led to the conclusion that S422L is pathogenic. We previously performed whole-genome sequencing in a family quartet of Ashkenazi Jewish decent with no history of J-wave syndrome. Re-examination of these data reveals that both parents are heterozygous for the S422L variant, while the 12-year old son carries two copies--thus representing the first reported case of a S422L homozygote. In order to examine whether the S422L mutation might segregate at appreciable frequencies in specific populations, we genotyped the variant in a panel consisting of 722 individuals from 22 European, Middle Eastern non-Jewish, Ashkenazi Jewish, and non-Ashkenazi Jewish populations. We found that the S422L allele was at a significantly higher frequency in Ashkenazi Jews (~4%) compared with other populations in our survey, which have frequencies <0.25%. We also performed ECGs in both male members of the family quartet. The homozygous boy demonstrated no clinically significant ECG abnormalities, while the heterozygous father presented with a subtle J-wave point elevation. Our results suggest that either (a) previous studies implicating S422L as pathogenic for J-wave syndromes failed to appropriately account for European population structure and the variant is likely benign, or (b) Ashkenazi Jews may be at significantly increased risk of J-wave syndromes and ultimately sudden cardiac death.


Asunto(s)
Predisposición Genética a la Enfermedad , Judíos/genética , Canales KATP/genética , Fibrilación Ventricular/genética , Niño , Muerte Súbita Cardíaca/etiología , Europa (Continente) , Frecuencia de los Genes , Genoma Humano , Genotipo , Haplotipos , Homocigoto , Humanos , Masculino , Mutación , Factores de Riesgo , Fibrilación Ventricular/patología
17.
Epilepsia ; 54(7): 1270-81, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23647072

RESUMEN

PURPOSE: The management of epilepsy in children is particularly challenging when seizures are resistant to antiepileptic medications, or undergo many changes in seizure type over time, or have comorbid cognitive, behavioral, or motor deficits. Despite efforts to classify such epilepsies based on clinical and electroencephalographic criteria, many children never receive a definitive etiologic diagnosis. Whole exome sequencing (WES) is proving to be a highly effective method for identifying de novo variants that cause neurologic disorders, especially those associated with abnormal brain development. Herein we explore the utility of WES for identifying candidate causal de novo variants in a cohort of children with heterogeneous sporadic epilepsies without etiologic diagnoses. METHODS: We performed WES (mean coverage approximately 40×) on 10 trios comprised of unaffected parents and a child with sporadic epilepsy characterized by difficult-to-control seizures and some combination of developmental delay, epileptic encephalopathy, autistic features, cognitive impairment, or motor deficits. Sequence processing and variant calling were performed using standard bioinformatics tools. A custom filtering system was used to prioritize de novo variants of possible functional significance for validation by Sanger sequencing. KEY FINDINGS: In 9 of 10 probands, we identified one or more de novo variants predicted to alter protein function, for a total of 15. Four probands had de novo mutations in genes previously shown to harbor heterozygous mutations in patients with severe, early onset epilepsies (two in SCN1A, and one each in CDKL5 and EEF1A2). In three children, the de novo variants were in genes with functional roles that are plausibly relevant to epilepsy (KCNH5, CLCN4, and ARHGEF15). The variant in KCNH5 alters one of the highly conserved arginine residues of the voltage sensor of the encoded voltage-gated potassium channel. In vitro analyses using cell-based assays revealed that the CLCN4 mutation greatly impaired ion transport by the ClC-4 2Cl(-) /H(+) -exchanger and that the mutation in ARHGEF15 reduced GEF exchange activity of the gene product, Ephexin5, by about 50%. Of interest, these seven probands all presented with seizures within the first 6 months of life, and six of these have intractable seizures. SIGNIFICANCE: The finding that 7 of 10 children carried de novo mutations in genes of known or plausible clinical significance to neuronal excitability suggests that WES will be of use for the molecular genetic diagnosis of sporadic epilepsies in children, especially when seizures are of early onset and difficult to control.


Asunto(s)
Epilepsia/genética , Exoma/fisiología , Predisposición Genética a la Enfermedad , Mutación/genética , Adolescente , Animales , Arginina/genética , Línea Celular , Niño , Preescolar , Canales de Potasio Éter-A-Go-Go/genética , Femenino , Factores de Intercambio de Guanina Nucleótido/genética , Humanos , Lactante , Masculino , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/genética , Oocitos , Técnicas de Placa-Clamp , Proteínas Serina-Treonina Quinasas/genética , Análisis de Secuencia de ADN , Transducción Genética , Transfección , Xenopus laevis , Proteína de Unión al GTP rhoA/metabolismo
18.
Am J Hum Genet ; 92(3): 454-9, 2013 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-23453668

RESUMEN

We report the discovery of an African American Y chromosome that carries the ancestral state of all SNPs that defined the basal portion of the Y chromosome phylogenetic tree. We sequenced ∼240 kb of this chromosome to identify private, derived mutations on this lineage, which we named A00. We then estimated the time to the most recent common ancestor (TMRCA) for the Y tree as 338 thousand years ago (kya) (95% confidence interval = 237-581 kya). Remarkably, this exceeds current estimates of the mtDNA TMRCA, as well as those of the age of the oldest anatomically modern human fossils. The extremely ancient age combined with the rarity of the A00 lineage, which we also find at very low frequency in central Africa, point to the importance of considering more complex models for the origin of Y chromosome diversity. These models include ancient population structure and the possibility of archaic introgression of Y chromosomes into anatomically modern humans. The A00 lineage was discovered in a large database of consumer samples of African Americans and has not been identified in traditional hunter-gatherer populations from sub-Saharan Africa. This underscores how the stochastic nature of the genealogical process can affect inference from a single locus and warrants caution during the interpretation of the geographic location of divergent branches of the Y chromosome phylogenetic tree for the elucidation of human origins.


Asunto(s)
Negro o Afroamericano/genética , Cromosomas Humanos Y , ADN Mitocondrial/genética , África del Sur del Sahara , África Central , Linaje de la Célula , Femenino , Fósiles , Genética de Población/métodos , Humanos , Masculino , Filogenia , Polimorfismo de Nucleótido Simple
19.
J Hum Genet ; 58(3): 165-73, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23344321

RESUMEN

Indonesia, an island nation linking mainland Asia with the Pacific world, hosts a wide range of linguistic, ethnic and genetic diversity. Despite the complexity of this cultural environment, genetic studies in Indonesia remain surprisingly sparse. Here, we report mitochondrial DNA (mtDNA) and associated Y-chromosome diversity for the largest cohort of Indonesians examined to date-2740 individuals from 70 communities spanning 12 islands across the breadth of the Indonesian archipelago. We reconstruct 50 000 years of population movements, from mitochondrial lineages reflecting the very earliest settlers in island southeast Asia, to Neolithic population dispersals. Historic contacts from Chinese, Indians, Arabs and Europeans comprise a noticeable fraction of Y-chromosome variation, but are not reflected in the maternally inherited mtDNA. While this historic immigration favored men, patterns of genetic diversity show that women moved more widely in earlier times. However, measures of population differentiation signal that Indonesian communities are trending away from the matri- or ambilocality of early Austronesian societies toward the more common practice of patrilocal residence today. Such sex-specific dispersal patterns remain even after correcting for the different mutation rates of mtDNA and the Y chromosome. This detailed palimpsest of Indonesian genetic diversity is a direct outcome of the region's complex history of immigration, transitory migrants and populations that have endured in situ since the region's first settlement.


Asunto(s)
ADN Mitocondrial/genética , Variación Genética , Genética de Población/métodos , Cromosomas Humanos Y/genética , Emigración e Inmigración , Etnicidad/genética , Femenino , Haplotipos , Humanos , Indonesia , Masculino , Mitocondrias/genética , Islas del Pacífico , Filogenia , Dinámica Poblacional , Análisis de Secuencia de ADN
20.
Proc Natl Acad Sci U S A ; 109(25): 9781-5, 2012 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-22665788

RESUMEN

The sacred texts of five world religions (Buddhism, Christianity, Hinduism, Islam, and Judaism) use similar belief systems to set limits on sexual behavior. We propose that this similarity is a shared cultural solution to a biological problem: namely male uncertainty over the paternity of offspring. Furthermore, we propose the hypothesis that religious practices that more strongly regulate female sexuality should be more successful at promoting paternity certainty. Using genetic data on 1,706 father-son pairs, we tested this hypothesis in a traditional African population in which multiple religions (Islam, Christianity, and indigenous) coexist in the same families and villages. We show that the indigenous religion enables males to achieve a significantly (P = 0.019) lower probability of cuckoldry (1.3% versus 2.9%) by enforcing the honest signaling of menstruation, but that all three religions share tenets aimed at the avoidance of extrapair copulation. Our findings provide evidence for high paternity certainty in a traditional African population, and they shed light on the reproductive agendas that underlie religious patriarchy.


Asunto(s)
Paternidad , Religión , Conducta Sexual , Femenino , Humanos , Masculino , Linaje
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