Decoding paternal genetic architecture of Gujarati Brahmin population of India using 27 Y-STRs: Diversity, structure, and global comparison.

Y-Short Tandem Repeats (Y-STRs) are used in forensic cases to aid in individual identification and strengthen the understanding of peopling in India by assessing genetic differences. The current study aims to report the genetic variations present in the endogamous Brahmin population of Gujarat using 27 Y-STR markers. 421 unrelated male individuals were evaluated to characterize forensically relevant parameters, haplotype diversity, and haplogroup distribution. The genetic diversity, power of discrimination, and haplotype diversity observed were 0.701, 0.699, and 0.711, respectively. The Y- Haplogroup Predictor-NEVGEN was utilised to assess the haplogroup distribution. The R1a haplogroup was observed with the highest frequency (39%), followed by haplogroup L (15%) and haplogroup J (12%). Further, 3,213 Y-STR genotypes across 24 global populations were analysed using pairwise Rst value to assess the genetic affinity among them and significant p-values were obtained. The Multi-Dimensional Scaling (MDS) plot revealed a butterfly-like appearance with 0.9946 stress value. Moreover, AMOVA was performed to determine the variance within and among the populations. The Gujarati Brahmin population exhibited genetic similarities with the Rajasthan Brahmins, populations of Madhya Pradesh and West/North Europe. The intra-population network revealed a star-like topology for the haplogroup R1a along with the presence of ancestral haplogroups L, J and H spread across the network, reflecting accumulated mutations in the study cohort. The current study also adds to the existing Y-STR dataset of the Indian population and its utility in forensic and population studies.