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European Journal of Human Genetics (2010) 18, 354363 & 2010 Macmillan Publishers Limited All rights reserved 1018-4813/10 $32.00 http://www.nature.com/ejhg
Web End =www.nature.com/ejhg
ARTICLE
Traces of sub-Saharan and Middle Eastern lineages in Indian Muslim populations
Muthukrishnan Eaaswarkhanth1,2, Ikramul Haque*,1, Zeinab Ravesh2, Irene Gallego Romero3, Poorlin Ramakodi Meganathan1, Bhawna Dubey1, Faizan Ahmed Khan4, Gyaneshwer Chaubey5, Toomas Kivisild3,5, Chris Tyler-Smith6, Lalji Singh2 and Kumarasamy Thangaraj*,2
Islam is the second most practiced religion in India, next to Hinduism. It is still unclear whether the spread of Islam in India has been only a cultural transformation or is associated with detectable levels of gene ow. To estimate the contribution of West Asian and Arabian admixture to Indian Muslims, we assessed genetic variation in mtDNA, Y-chromosomal and LCT/MCM6 markers in 472, 431 and 476 samples, respectively, representing six Muslim communities from different geographical regions of India. We found that most of the Indian Muslim populations received their major genetic input from geographically close non-Muslim populations. However, low levels of likely sub-Saharan African, Arabian and West Asian admixture were also observed among Indian Muslims in the form of L0a2a2 mtDNA and E1b1b1a and J*(xJ2) Y-chromosomal lineages. The distinction between Iranian and Arabian sources was difcult to make with mtDNA and the Y chromosome, as the estimates were highly correlated because of similar gene pool compositions in the sources. In contrast, the LCT/MCM6 locus, which shows a clear distinction between the two sources, enabled us to rule out signicant gene ow from Arabia. Overall, our results support a model according to which the spread of Islam in India was predominantly cultural conversion associated with minor but still detectable levels of gene ow from outside, primarily from Iran and Central Asia, rather than directly from the Arabian Peninsula. European Journal of Human Genetics (2010) 18, 354363; doi:http://dx.doi.org/10.1038/ejhg.2009.168
Web End =10.1038/ejhg.2009.168 ; published online 7 October 2009
Keywords: Indian Muslims; mtDNA; Y chromosome; Middle East; sub-Saharan; gene ow
INTRODUCTIONIslam was rst brought to the Indian Subcontinent in 711 CE, when the Arab military forces conquered Sindh, the lower Indus valley, and incorporated it into the Arabian Empire.1 Subsequently, Sindh not only became an Indo-Muslim state but also an Islamic outpost, where Arabs established trade links with the Middle East and were later joined by mystic...