Background: Major population movements, social structure, and caste endogamy have influenced the genetic structure of Indian populations. An understanding of these influences is increasingly important as gene mapping and case-control studies are initiated in South Indian populations.

No abstract

No abstract

ErratumErratum to: Genetic adaptation to extreme hypoxia: Study of high-altitude pulmonary edema in a three-generation Han Chinese family [Blood Cells Mol. Dis. 43:3 (2009) The SNP positions were incorrectly annotated for the genome-wide SNP analysis. Reanalysis of the appropriate SNP positions indicates that none of the genes are associated with the reported phenotype, and we retract the statement that HIF2A could not be excluded based upon patterns of haplotype analysis and wish to remove the supplementary table.

Four families were selected randomly on the basis of the occurrence of spina-bifida cystica and/or spina bifida occulta in one or more family members. Sixty-three relatives were studied clinically and roentgenologically; their roentgenograms were evaluated blindly. Twenty-eight were clinically and roentgenologically normal; 35 were diagnosed as having spina bifida occulta (SBO), spina bifida cystica (SBC), vertebral anomalies, and/or external defects usually interpreted as evidence for SBO. Excluding one proband we found the frequency of SBO to be 19/51 (37%) and the frequency of all types of spinal/vertebral defects (excluding five probands) to be 30/58 (52%). The distribution of these defects in the four families was analyzed using likelihood methods corrected for random ascertainment. The log likelihood values for sporadic, recessive, and dominant models were -26.69, -20.95, and -18.90, respectively, indicating a higher likelihood of autosomal dominant inheritance than sporadic occurrence or recessive inheritance. The penetrance probability in this dominant model, estimated by maximum likelihood, is 0.749 +/- 0.100. Further examination of these data suggest that SBO and SBC represent different expressions of the same dominant gene in these kindreds.

The origins and genetic affinities of the more than 500 tribal populations living in South Asia are widely disputed. This may reflect differential contributions that continental populations have made to tribal groups in South Asia. We assayed for the presence of the intergenic COII/tRNALys 9-bp deletion in human mtDNA in 646 individuals from 12 caste and 14 tribal populations of South India and compared them to individuals from Africa, Europe, and Asia. The 9-bp deletion is observed in four South Indian tribal populations, the Irula, Yanadi, Siddi, and Maria Gond, and in the Nicobarese. Length polymorphisms of the 9-bp motif are present in the Santal, Khonda Dora, and Jalari, all of whom live in a circumscribed region on the eastern Indian coast. Phylogenetic analyses of mtDNA control region sequence from individuals with the 9-bp deletion indicate that it has arisen independently in some Indian tribal populations. Other 9-bp deletion haplotypes are likely to be of Asian and African origin, implying multiple origins of the 9-bp deletion in South India. These results demonstrate varying genetic affinities of different South Indian tribes to continental populations and underscore the complex histories of the tribal populations living in South Asia.

We report here retrospective data on 991 liveborn and stillborn infants with neural tube defects (NTDs) born to Utah residents from January 1, 1940 to December 31, 1979. Data were obtained from multiple sources including approximately 1.25 million vital statistics records and several hundred physician and hospital charts. Causal heterogeneity among NTD patients is presumed because 6% of our cases have other congenital anomalies not part of the NTD field defect. A significant association of NTDs with oral clefts is noted. Sex ratios and empiric recurrence risks for isolated NTDs and NTDs associated with other major malformations are also calculated.

No abstract