Forensic Evidence for Cytochrome b Gene SNPs in Obese and Non Obese Saudi Arabians

Abstract

Oral swabs from obese and non obese Saudi Arabians from both sexes with an average age of 35 years old were collected and their DNAs were extracted. PCR for 1000 bp of the mitochondrial cytochrome b (cytb) gene was conducted and the amplified products were sequenced in order to determine the possible forensic or obesity-related SNPs. Alignment of the obtained sequences with its counterparts of 100 healthy Afro-Asians deposited in the Genbank was undertaken and the polymorphic sites were compared. Sixteen Single Nucleotide Polymorphic sites (SNPs) and 26 variations were noted. From the 26 variations, sixteen were synonymous and the other 10 were non-synonymous. Four common haplogroups were determined using Mitomaster software (H2a, JT, U5a and R0a). Most of SNPs were related to tribes more than to obesity and the major SNP (C15452A) was recorded in both obese and non obese haplotypes. Two non-synonymous amino acid changes were found in 2 obese males (H15 and H27; A15043G) and 2 obese females (H48 and H51; C15677A) indicating that both SNPs could be obesity markers. In conclusion, cytb gene is reasonably applicable in forensic purpose while it was unclear to be used as an obesity marker. It needs to be examined for hundreds of unrelated obese and non obese people.