title: Heteroplasmy in hair: differences among hair and blood from the same individuals are still a matter of debate.
abstract: The analysis of mitochondrial DNA (mtDNA) is a useful tool in forensic cases when sample contents too little or degraded nuclear DNA to genotype by autosomal short tandem repeat (STR) loci, but it is especially useful when the only forensic evidence is a hair shaft. Several authors have related differences in mtDNA from different tissues within the same individual, with high frequency of heteroplasmic variants in hair, as also in some other tissues. Is still a matter of debate how the differences influence the interpretation forensic protocols. One difference between two samples supposed to be originated from the same individual are related to an inconclusive result, but depending on the tissue and the position of the difference it should have a different interpretation, based on mutation-rate heterogeneity of mtDNA. In order to investigate it differences in the mtDNA control region from hair shafts and blood in our population, sequences from the hypervariable regions 1 and 2 (HV1 and HV2) from 100 Brazilian unrelated individuals were compared. The frequency of point heteroplasmy observed in hair was 10.5% by sequencing. Our study confirms the results related by other authors that concluded that small differences within tissues should be interpreted with caution especially when analyzing hair samples.
authors: UNESP, Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, Laboratório de Investigação de Paternidade, Rodovia Araraquara-Jaú, Km 1, Campus, 14801-902 Araraquara, SP, Brazil. greiciane_gp@hotmail.com
authors: Greiciane G
authors: GG
authors: Paneto
authors: Joyce A
authors: JA
authors: Martins
authors: Larissa V G
authors: LV
authors: Longo
authors: Gabriella A
authors: GA
authors: Pereira
authors: Adriana
authors: A
authors: Freschi
authors: Vera L S
authors: VL
authors: Alvarenga
authors: Bety
authors: B
authors: Chen
authors: Rogério N
authors: RN
authors: Oliveira
authors: Mário H
authors: MH
authors: Hirata
authors: Regina M B
authors: RM
authors: Cicarelli
mesh_terms: D022801:Complementarity Determining Regions / Q000235:genetics* / Q000378:metabolism; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000378:metabolism*; D053803:Forensic Genetics; D006197:Hair / Q000378:metabolism*; D006801:Humans; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D022801:Complementarity Determining Regions; D017931:DNA Primers; D004272:DNA, Mitochondrial