Variant 1859G→A (Arg620Gln) of the Hairless Gene: Absence of Association with Papular Atrichia or Androgenetic Alopecia

May represent a unique founding lineage in American Indians. To evaluate further the origin of haplogroup X in North and Central America, we have examined the presence of this mtDNA haplotype in Altaian populations from South Siberia, which is located between Europe and East Asia. The Altaian population (total number = 49) sam- pled by us was recruited from villages near Gorno-Altaisk (the capital city of the Altai Republic). All individuals sampled spoke Altaic as their native language and had no known recent admixture with other ethnic groups. DNA was isolated from 5 ml of whole blood, using the salting-out procedure (Miller et al. 1988). The complete mtDNA control region sequence for each individual was determined, following PCR amplification and direct se- quencing (see Stoneking et al. 1997). Haplogroup X lineages were identified based on the distribution of three diagnostic RFLP haplotypes (HpaI at nucleotide positions 7028 and 7389; MspI at nucleotide position 10394) previously described by Brown et al. (1998). A single Altaian individual (ALT-3) exhibited all three diagnostic markers associated with haplogroup X RFLPs, confirming her membership in this haplogroup (fig. 1A). Phylogenetic analysis of the entire mtDNA control region sequence of ALT-3 revealed that it was most closely related to the Ojibwa haplogroup X con- sensus, but distinctly different from both European and Navajo haplogroup X sequences (fig. 1B). Thus, our re- sults unambiguously demonstrate the presence of hap- logroup X mtDNAs among Altaians and provide fur- ther support for its Amerindian origin. 238 Figure 1 Haplogroup X in an Altaian individual. A, Distribution of haplogroup X diagnostic RFLP markers. B, Phylogenetic tree of 16S rRNA gene se- quences from haplogroup X mtDNAs. The tree was constructed by neighbor-joining methods, and length of branches corresponds to genetic distance. Bootstrap values are indicated at nodes. The Altaian sample (ALT-3) clusters most