Field L L, Surje S, Ray A K
Department of Pediatrics, University of Calgary, Canada.
Am J Phys Anthropol. 1988 Jan;75(1):31-5. doi: 10.1002/ajpa.1330750105.
The populations of India are genetically diverse, both within and between geographic regions; immunoglobulin (GM) allotypes provide important information on genetic differences between populations, since the frequencies of combinations of allotypes (termed "haplotypes") vary dramatically among ethnic groups. As part of a project to assess genetic diversity among defined Indian populations, we have examined eight GM allotypes in a sample of 101 unrelated Sikhs who have migrated to Toronto, Canada: Glm(1, 2, 3, 17) and G3m (5, 15, 16, 21). Sikhs are a religious group that arose in the Punjab about 1500 A.D.; most of the original converts are believed to have been middle to upper-middle caste Hindus. Gm allotyping showed that six Gm haplotypes occurred at polymorphic frequencies (greater than 0.01) in Sikhs: Gm3;5, Gm1,17;21, Gm1,2,17;21, Gm1,17;5, Gm1,17;15,16, and Gm1,3;5. These haplotypes have all been previously reported in Indian populations. The frequencies of the first four haplotypes resembled the published frequencies for lower-caste Hindus of NW India more than upper-caste Hindus. However, the last two haplotypes have been found only in upper-caste Hindus. The frequency of one of these, Gm1,17;15,16 was higher in Sikhs (0.09) than has been reported in any Indian population with the exception of Parsis (who are descended from Iranians). We speculate that the high frequency of this haplotype may have been characteristic of some of the Hindu castes in the Punjab from which Sikhs are descended.
印度的人口在地理区域内部和之间都具有遗传多样性；免疫球蛋白（GM）同种异型为人群之间的遗传差异提供了重要信息，因为同种异型组合（称为“单倍型”）的频率在不同种族群体中差异很大。作为评估特定印度人群遗传多样性项目的一部分，我们在101名移民到加拿大多伦多的不相关锡克教徒样本中检测了八种GM同种异型：Glm(1, 2, 3, 17)和G3m (5, 15, 16, 21)。锡克教徒是一个宗教群体，大约在公元1500年出现在旁遮普邦；大多数最初的皈依者据信是中上层种姓的印度教徒。GM分型显示，六种GM单倍型在锡克教徒中以多态频率（大于0.01）出现：Gm3;5、Gm1,17;21、Gm1,2,17;21、Gm1,17;5、Gm1,17;15,16和Gm1,3;5。这些单倍型此前均在印度人群中被报道过。前四种单倍型的频率与印度西北部低种姓印度教徒的已公布频率更为相似，而非高种姓印度教徒。然而，最后两种单倍型仅在高种姓印度教徒中被发现。其中一种，Gm1,17;15,16，在锡克教徒中的频率（0.09）高于除帕西人（他们是伊朗人的后裔）外的任何印度人群体中所报道的频率。我们推测，这种单倍型的高频率可能是锡克教徒所源自的旁遮普邦某些印度教种姓的特征。
