Sulfation pharmacogenetics: SULT1A1 and SULT1A2 allele frequencies in Caucasian, Chinese and African-American subjects

Sulfotransferase (SULT) enzymes catalyze the sulfate conjugation of drugs, other xenobiotics, neurotransmitters and hormones. The genes for SULT1A1 an d SULT1A2 contain common genetic polymorphisms that are associated with ind ividual variations in levels of enzyme activity as well as variations in bi ochemical and physical properties. We set out to compare the frequencies of common SULT1A1 and SULT1A2 alleles in Caucasian, Chinese and African-Ameri can subjects. Allele frequencies for SULT1A1*1, *2 and *3 in 242 Caucasian subjects were 0.656, 0.332 and 0.012, respectively. Frequencies of those sa me alleles were significantly different in 290 Chinese subjects: 0.914, 0.0 80 and 0.006, respectively, as were frequencies in 70 African-American subj ects: 0.477, 0.294 and 0.229, respectively. Ethnic variation in allele freq uencies was also observed for SULT1A2, with frequencies in Caucasian subjec ts for SULT1A2*1, *2 and *3 of 0.507, 0.389 and 0.104; frequencies in Chine se of 0.924 and 0.076 with no *3 alleles observed; and, finally, in African -Americans frequencies of 0.637, 0.249 and 0.114, respectively. We also fou nd that SULT1A1*2 and SULT1A2*2, the most common variant alleles for these two genes, were in positive linkage disequilibrium in all three populations studied, with D' values of 0.776 in Caucasian (P < 0.001), 0.915 in Chines e (P < 0.001) and 0.864 in African-American subjects (P < 0.001). These obs ervations represent a step towards determining the possible functional impl ications for individual variations in sulfate conjugation of common genetic polymorphisms for SULT1A1 and SULT1A2. Pharmacogenetics 11:57-68 (C) 2001 Lippincott Williams & Wilkins.