Genotype analysis using human hair shaft.

Analysis of genotypes for genetic predisposition of diseases has profound and widespread clinical application and has become a fundamental tool in the study of molecular epidemiology. In this study, we report a convenient and completely noninvasive approach to perform genotyping using terminal cephalic hair shaft. The average and median DNA amounts purified from the hair shaft are 112 +/- 180 (1 SD) pg/mg and 66 pg/mg of hair shaft, respectively. Using hybridization with molecular beacons that can reliably distinguish single nucleotide polymorphisms at different alleles, we are able to analyze the genotypes of APO-E and G-protein beta3 (GNB3) subunit C825T loci in DNA samples obtained from hair shaft in a high throughput format. The amount of DNA obtained from 20 mg of hair shaft is sufficient for multiple independent genotyping assays. These findings demonstrate that terminal hair shaft provides a convenient and reliable genomic DNA source for an analysis of genotypes.