SNPs in mitochondrial DNA coding region used to discriminate common sequences in HV1–HV2–HV3 region

Abstract

Regions HV1, HV2 and HV3 of mitochondrial DNA (mtDNA) are routinely analyzed for forensic and evolutionary purposes due to the high polymorphic rate but sometimes show limited power of discrimination since several polymorphisms are very common in different populations. Genotyping additional SNPs in the coding region of mtDNA have been suggested to increase the power of discrimination between individuals who show common haplotypes in control region. Herein, we intended to evaluate the discrimination power of 26 SNPs from coding region, previously described, in 15 pairs of mother/child who could not be previously individualized and matched by HV1–HV2–HV3 analysis. These 15 pairs were divided into 7 groups of common sequences, of which 2 presented European haplogroup (Hg) H, 2 showed Amerindian Hg B4, 4 Amerindian Hg C1b (but with 2 different haplotypes), 3 African Hg L3e2b, 2 African Hg L3e1 and 2 African Hg L1b. Sequencing was performed using BygDye Terminator v3.1; capillary electrophoresis was performed on ABI3130. The SNPs were determined by comparison of the sequences obtained with reference sequence rCRS. After sequencing we could find 43 SNPs to analyze. Twenty-six out of 43 SNPs, in different combinations, were able to distinguish all pairs of mother/child except two from Hg L3e2b. The SNP 8047, observed here is not report in MITOMAP. This can be a preliminary result in the direction of having a SNP set that could be used to discriminate common sequences in mitochondrial control region in a highly mixed and heterogeneous population as the Brazilian one.