Y-Chromosomal insights into the paternal genealogy of the Kerey tribe have called into question their descent from the Stepfather of Genghis Khan

TL;DR

Y-chromosome analysis of 207 Kerey tribe males identifies two prevalent paternal lineages, C2-FT411734 in the Abak clan and C2-FT224144 in the Ashamaily clan, indicating common ancestry but not full sibling status. The genetic evidence supports Kerey kinship with the Uissun tribe while refuting several ethnographic hypotheses, including descent from Genghis Khan’s stepfather.

Key findings

• Among 207 Kerey males, C2-M217 was the most prevalent haplogroup at 85.8%; the two dominant lineages within C2a1a3a-F3796/C2*-Star Cluster were C2-FT411734 in Abak (69.8%) and C2-FT224144 in Ashamaily (77.3%).
• TMRCA estimates were ~1337 CE (95% CI: 1072–1540 CE) for C2-FT411734 and ~1139 CE (95% CI: 845–1369 CE) for C2-FT224144, with a common ancestor C-F5481 around the mid-9th century, not supporting Abak and Ashamaily as brothers in traditional genealogy.
• Genetic diversity was low: 104 unique haplotypes among 207 males, HD = 0.068, DC = 50.2%, HMP = 0.096; rapid-mutating Y-STRs did not sufficiently differentiate lineages within Abak and Ashamaily.
• Kinship with the Uissun tribe was supported, with closest average RST values to Alban (0.0592), Dulat (0.0832), Suan (0.09852), and Shapyrashty (0.1297), but the claim that Abak originated from Uissun was refuted because C2-Y12782 sub-lineage C2-FT224144 marks Ashamaily. Hypotheses linking Kerey with Uak, Sirgeli, Adai, Törtkara, Karakerey, and Kereyit were not supported.

Methods

• The study analyzed 207 healthy Kazakh males from the Kerey tribe, including Ashamaily (N = 154) and Abak (N = 53), with ancestors three generations prior from Kazakhstan (N = 158), Mongolia (N = 21), China (N = 19), and Russia (N = 9); venous blood samples were collected from 15 November 2020 to 15 November 2021.
• DNA was extracted and genotyped for 23 Y-STRs using the PowerPlex Y23 kit and 37 Y-SNPs using TaqMan assays; haplogroups were assigned with Nevgen and FamilyTreeDNA Discover, supplemented by citizen science BigY data.
• Statistical analyses used STRAF 1.0.5 for haplotype/allele frequencies, HD, HMP, DC, and forensic parameters; Haplomatch for haplotype comparison; a compiled dataset of 3856 published 17-Y-STR Kazakh haplotypes; and median-joining networks built with Network/Network Publisher using 15 or 21 Y-STRs, Reduced-Median algorithms, DYS389I subtracted from DYS389II, and DYS385a/b excluded.

Limitations

• The paper states that the Uak tribe sample size of 11 was insufficient for RST calculation and was not shown on the MDS graph, and that available material on the Uak clan level was insufficient to substantiate ethnographic accounts.
• The paper states that knowledge of Y-chromosome variants in the Kereyit clan is limited, based on only four individuals, and that further investigation is necessary to confirm any association with the medieval Kereyit tribe.
• Evident from the text: the PowerPlex Y23 panel showed insufficient power to differentiate close paternal clan members in the Kerey tribe, and rapid-mutating Y-STRs did not differentiate lineages within Abak and Ashamaily.