Genetic landscape of the Brahmin population of Gujarat, India, using X-chromosome STR markers

X-chromosome Short Tandem Repeats (X-STR) have been utilized in forensics and population genetics studies for more than two decades, particularly in cases involving complex kinship analysis, disaster victim identification, sexual assault, and incest. Nevertheless, the genetic landscape of India remains underexplored using X-STR markers. In the present study, blood samples of 420 unrelated participants (133 females and 287 males) were analyzed from the Brahmin community of Gujarat, India. For the amplification of X-STR loci, the Investigator^® Argus X-12 QS Kit was utilized. 186 unique alleles were identified, suggesting high genetic diversity of the Brahmin population. Locus DXS10135 (PIC = 0.930) was the most polymorphic, and locus DXS7423 was the least polymorphic (PIC = 0.553). On analyzing the haplotype diversity, Linkage Group-1 (LG1) was found to have the highest haplotype diversity (0.997). Notably, LG1 was also the most informative and polymorphic linkage group (PIC = 0.994), preceded by LG4 (PIC = 0.989), LG2 (PIC = 0.988), and LG3 (PIC = 0.983). Based on the allelic and haplotype frequencies, the combined estimates for PD_F, PD_M, MEC_Desmarais, MEC_Kishida, MEC_Kruger, and MEC_{Desmarais duo} were ≥ 0.999, demonstrating high discriminatory power of all the loci. Furthermore, inter-population phylogenetic analysis revealed high genetic affinity of Gujarat's Brahmins with other populations of the Indian subcontinent, encompassing Madhya Pradesh's Bhil tribe and Punjab's Jat Sikh. The Gujarat Brahmins also have a shorter genetic distance with other South Asian populations, including the Bangladeshi population. This research indicates that the studied X-STR markers are highly polymorphic, offering significant insights for individual identification in forensics.