Project description:The Ashkenazi Jewish population has long been considered a genetic isolate and presumed to have the genetic signatures of founder effects and isolation. We genotyped a large cohort of Ashkenazi Jews and analyzed their genetic structure compared to other worldwide populations. We genotyped 471 normal control Ashkenazi Jewish individuals with the Affymetrix 6.0 array and analyzed their genetic structure relative to other Europe and worldwide populations. We measured heterozygosity, linkage disequilibrium, identity-by-descent and used extended haplotype tests of positive selection.
Project description:The Ashkenazi Jewish population has long been considered a genetic isolate and presumed to have the genetic signatures of founder effects and isolation. We genotyped a large cohort of Ashkenazi Jews and analyzed their genetic structure compared to other worldwide populations.
Project description:Schizophrenia is a severe psychiatric illness that affects ~1% of the population and has a strong genetic underpinning. Recently, genome wide analysis of copy number variation (CNV) has implicated rare and de novo events as important in schizophrenia. Here we report a genome-wide analysis of 245 schizophrenia cases and 490 controls, all of Ashkenazi Jewish descent. Since many studies have found an excess burden of large, rare deletions in cases, we limited our analysis to deletions over 500 kb in size. We observed seven large, rare deletions in cases with 57% of these being de novo. We focused on one 836 kb de novo deletion at chromosome 3q29 that falls within a 1.3–1.6 Mb deletion previously identified in children with intellectual disability (ID) and autism, as increasing evidence suggests an overlap of specific rare CNVs between autism and schizophrenia. By combining our data with prior CNV studies of schizophrenia and analysis of the data of the Genetic Association Information Network (GAIN), we identified six 3q29 deletions among 7,545 schizophrenic subjects and one among 39,748 controls, resulting in a statistically significant association with schizophrenia (p = 0.02) and an odds ratio estimate of 17 (95% CI: 1.36–1198.4). Moreover, this 3q29 deletion region contains two linkage peaks from prior schizophrenia family studies, and the minimal deletion interval implicates 20 annotated genes, including PAK2 and DLG1, both paralogous to X-linked ID genes and now strong candidates for schizophrenia susceptibility. Copy Number alanysis was performed on 245 cases and 490 controls of Ashkenazi Jewish descent. Samples were analyzed for deletions greater than 500 kb, with 20 or more snps in the interval. Three algorithms were used for analysis, GADA, GLAD and BEAST. The reference was created by using all samples processed here as the reference.
Project description:Contemporary Jews comprise an aggregate of ethno-religious communities whose worldwide members identify with each other through various shared religious, historical, and cultural traditions1,2. Historical evidence suggests common origins in the Middle East, followed by migrations leading to the establishment of communities of Jews in Europe, Africa, and Asia - in what is termed the Jewish Diaspora3-5. This complex demographic history imposes special challenges in attempting to address the genetic structure of the Jewish people6. While many genetic studies have shed light on Jewish diseases and origins, including those focusing on uniparentally- and biparentally-inherited markers7-16, genome-wide patterns of variation across the vast geographic span of Jewish Diaspora communities and their respective neighbors have yet to be addressed. Here we use high-density bead arrays to genotype individuals from 14 Jewish Diaspora communities, and compare these patterns of genome-wide diversity with those from 69 Old World non-Jewish populations, of which 25 have not been previously reported. These samples were carefully chosen to provide comprehensive comparisons between Jewish and non-Jewish populations in the Diaspora, as well as with non-Jewish populations from the Middle East and North Africa. Principal component and structure-like analyses identify previously unrecognized genetic substructure within the Middle East. Most Jewish samples form a remarkably tight sub-cluster that overlies Druze and Cypriot samples, but not samples from other Levantine populations or paired Diaspora host populations. In contrast, Ethiopian Jews (Beta Israel) and Bene Israel Indian Jews cluster with neighbouring autochthonous populations in Ethiopia and western India, respectively; despite a clear paternal link between the Bene Israel and the Levant. These results cast light on the variegated genetic architecture of the Middle East, and trace the origins of most Jewish Diaspora communities to the Levant.
Project description:The Kashmiri population is an ethno-linguistic group that resides in the Kashmir Valley in northern India. A longstanding hypothesis is that this population derives ancestry from Jewish and/or Greek sources. There is historical and archaeological evidence of ancient Greek presence in India and Kashmir. Further, some historical accounts suggest ancient Hebrew ancestry as well. To date, it has not been determined whether signatures of Greek or Jewish admixture can be detected in the Kashmiri population. Using genome-wide genotyping and admixture detection methods, we determined there are no significant or substantial signs of Greek or Jewish admixture in modern-day Kashmiris. The ancestry of Kashmiri Tibetans was also determined, which showed signs of admixture with populations from northern India and west Eurasia. These results contribute to our understanding of the existing population structure in northern India and its surrounding geographical areas.
Project description:Contemporary Jews comprise an aggregate of ethno-religious communities whose worldwide members identify with each other through various shared religious, historical, and cultural traditions1,2. Historical evidence suggests common origins in the Middle East, followed by migrations leading to the establishment of communities of Jews in Europe, Africa, and Asia - in what is termed the Jewish Diaspora3-5. This complex demographic history imposes special challenges in attempting to address the genetic structure of the Jewish people6. While many genetic studies have shed light on Jewish diseases and origins, including those focusing on uniparentally- and biparentally-inherited markers7-16, genome-wide patterns of variation across the vast geographic span of Jewish Diaspora communities and their respective neighbors have yet to be addressed. Here we use high-density bead arrays to genotype individuals from 14 Jewish Diaspora communities, and compare these patterns of genome-wide diversity with those from 69 Old World non-Jewish populations, of which 25 have not been previously reported. These samples were carefully chosen to provide comprehensive comparisons between Jewish and non-Jewish populations in the Diaspora, as well as with non-Jewish populations from the Middle East and North Africa. Principal component and structure-like analyses identify previously unrecognized genetic substructure within the Middle East. Most Jewish samples form a remarkably tight sub-cluster that overlies Druze and Cypriot samples, but not samples from other Levantine populations or paired Diaspora host populations. In contrast, Ethiopian Jews (Beta Israel) and Bene Israel Indian Jews cluster with neighbouring autochthonous populations in Ethiopia and western India, respectively; despite a clear paternal link between the Bene Israel and the Levant. These results cast light on the variegated genetic architecture of the Middle East, and trace the origins of most Jewish Diaspora communities to the Levant. 466 samples are analysed on three different Illumina platforms.