Collagen Ialpha1 and vitamin D receptor gene polymorphisms in South African whites, blacks and Indians.

Abstract

To determine whether polymorphic differences exist between black, white and Indian South Africans in genes associated with bone mineral density and osteoporosis. Genes selected were the vitamin D receptor (Apa I and Taq I polymorphisms) and collagen (Sp I transcription factor polymorphism) using standard molecular biology techniques. Department of Chemical Pathology, Nelson R Mandela School of Medicine, University of Natal, Durban, South Africa. Healthy male and female blood donors living in the Durban metropolitan region, South Africa. The group comprised black Africans (n=264), white Caucasians (n=247) and Asians of Indian origin (n=194). No significant differences in genotypes were seen between white and Indian subjects. Blacks had a significantly higher frequency of the TT Taq I genotype and a significantly lower frequency of the Ss Sp I genotype. No ss genotype was detected in blacks. The very low frequency of the collagen Sp I s allele and higher frequency of the VDR T allele in blacks may be associated with the lower incidence of osteoporosis in this ethnic group.