Phylogenic tree of the 41 observed POU5F1 haplotypes. The tree was created using the neighbor-joining method in MEGA (version 3.1). The branch line length is proportional to the number of nucleotide differences between haplotypes from the root. The polymorphisms in each haplotype are ordered from 5' to 3', in the same order as the polymorphisms listed in Table 2, and the first site in each triplet is listed as the column heading. The (.) indicates that the allele is the same as the first haplotype in the tree. The (-) indicates a deletion, and the (+) indicated an insertion. Haplotypes unique to the African-descent population are indicated by the white triangles, those unique to the European-descent population are indicated by white squares, and those observed in both populations are indicated by black circles.