Genetic analysis of X‑chromosomal short tandem repeat (X‑STR) frequencies in Arab Iraqi male population.

Background: The X-chromosome short tandem repeat (STR) polymorphisms are a particular tool in the felds of human population genetics and personal identifcation. It was necessary in investigating complex kinship or def‑ ciency cases in conditions where information on mitochondrial DNA (mtDNA) or Y chromosome polymorphisms have been used to explore their direct paternal line. This study aimed to investigate the allele frequency of (12X-STR) of 200 unrelated males from diferent region of Baghdad City to serve as a reference data base for individual identifcation in Iraqi population. Results: Twelve X-STR loci (DXS7424, HPRTB, DXS8377, GATA31E08, DXS7423, DXS8378, DXS9895, DXS10074, DXS6809, DXS7133, DXS101, DXS6807) were successfully amplifed by multiplex PCR and divided into four groups. According to measures of allele frequency, the higher alleles frequency were 16, 11, 46, 11, 14, 10, 15, 15.2, 35, 11, 25, and 11 while the lowest alleles frequency were 11, 9, 52,53, 7, 17, 14, 13, 12.2,17, 36, 15, 16, 22, 29, and 17 that observed at the 12 loci respectively. Forensic efciency parameter for DXS8377 locus in the frst group showed high‑ est polymorphic allele in the Iraqi Arab population with the frequencies ranging from 0.005 to 0.16%. The power of discrimination (PD) value ranged from 0.663 for DXS7423 locus and 0.9066 for DXS8377 locus. In addition, the poly‑ morphism information content (PIC) value ranged from 0.602974 for DXS7423 locus to 0.899206 for DXS8377 locus. Conclusions: Overall the X-STR markers become used as an important source of information beside the autosomal and Y-STR markers, especially for kinship testing and haplotype analysis. [ABSTRACT FROM AUTHOR]