Population studies of polymorphisms of the serotonin transporter protein gene

The range of allele frequency variation in humans for any locus that may ha ve functionally important genetic variation needs to be documented. Therefo re, we tested two polymorphisms at the serotonin transporter protein locus (SLC6A4) in samples from seven specific populations from five continental r egions, We studied the promoter polymorphism which is reported to have func tional significance and to be associated with anxiety- and depression-relat ed phenotypes [Lesch et al,, 1996: Science 274:1527-1531], and the intron 2 VNTR polymorphism [Lesch et al,, 1994: J Neural Transm 95:157-162], Allele frequencies for both systems show significant global variation, and conseq uently so do haplotype frequencies. Linkage disequilibrium varied among the populations, being absent in some and highly significant in others. These differences further document a large potential for population stratificatio n in association studies of either of these SLC6A4 polymorphisms. Am. J. Me d. Genet. (Neuropsychiatr. Genet;) 88:61-66, 1999. (C) 1999 Wiley-Liss, Inc .