Masimirembwa C M, Johansson I, Hasler J A, Ingelman-Sundberg M
Department of Biochemistry, University of Zimbabwe, Harare.
Pharmacogenetics. 1993 Dec;3(6):275-80. doi: 10.1097/00008571-199312000-00001.
The objective of this study was to determine the CYP2D6 genotype of a black Zimbabwean population. Genotyping was carried out using Eco RI and Xba I RFLP, and allele-specific PCR amplification. Of 114 Zimbabwean samples analysed, no individual homozygous for any of the defect allelic forms CYP2D6A, CYP2D6B or CYP2D6D or combinations thereof was found. The allele frequencies of the three defect genes were 0, 1.8 and 3.9%, respectively. No subject carrying the Xba I 44 kb haplotype, indicative for poor metabolizers among Caucasians, was identified, whereas five individuals being heterozygous with a 29/42 kb haplotype were seen. Three out of the four CYP2D6B alleles found were associated with the 29/42 kb haplotype. Our findings are in agreement with the 0-2% prevalence of poor metabolizers (PMs) in the black populations previously phenotyped. The very low frequency of the CYP2D6B allele in the Zimbabwean population is different from very recent data from black Americans (allele frequency = 8.5%) and might indicate the Caucasian ancestry of this allele. Taken together, our data indicate important interethnic differences in the CYP2D locus between Caucasian, Asian and different black populations.
本研究的目的是确定津巴布韦黑人人群的CYP2D6基因型。使用Eco RI和Xba I限制性片段长度多态性（RFLP）以及等位基因特异性PCR扩增进行基因分型。在分析的114份津巴布韦样本中，未发现任何个体对CYP2D6A、CYP2D6B或CYP2D6D等任何缺陷等位基因形式或其组合呈纯合状态。这三个缺陷基因的等位基因频率分别为0%、1.8%和3.9%。未鉴定出携带Xba I 44 kb单倍型（在白种人中指示代谢不良者）的受试者，而观察到五名个体为29/42 kb单倍型的杂合子。所发现的四个CYP2D6B等位基因中有三个与29/42 kb单倍型相关。我们的研究结果与先前已进行表型分析的黑人人群中代谢不良者（PMs）0 - 2%的患病率一致。津巴布韦人群中CYP2D6B等位基因的极低频率与美国黑人的最新数据（等位基因频率 = 8.5%）不同，这可能表明该等位基因具有白种人血统。综上所述，我们的数据表明在白种人、亚洲人和不同黑人人群之间，CYP2D基因座存在重要的种族间差异。
