THE VS AND V BLOOD-GROUP POLYMORPHISMS IN AFRICANS - A SEROLOGIC AND MOLECULAR ANALYSIS

BACKGROUND: VS and V are common red cell antigens in persons of Africa n origin. The molecular background of these Rh system antigens is poor ly understood. STUDY DESIGN AND METHODS: Red cells from 100 black Sout h Africans and 43 black persons from Amsterdam, the Netherlands, were typed serologically for various Rh system antigens. Allele-specific po lymerase chain reaction and sequencing of polymerase chain reaction pr oducts were used to analyze C733G (Leu245Val) and G1006T (Gly336Cys) p olymorphisms in exons 5 and 7 of RHCE and the presence of a D-CE hybri d exon 3. RESULTS: The respective frequencies of all VS+ and of VS+ V- (r'(s)) phenotypes were 43 percent and 9 percent in the South African s and 49 percent and 12 percent in the Dutch donors. All VS+ donors ha d G733 (Val245), but six with G733 were VS- (4 V+(w), 2 V-). The four VS-V+(w) donors with G733 appeared to have a CE-D hybrid exon 5. T1006 (Cys336) was present in 12 percent and 16 percent of donors from the two populations. With only a few exceptions, T1006, a D-CE hybrid exon 3, and a C410T (Ala137Val) substitution were associated with a VS+ V- phenotype ((C)ce(s) or r'(s) haplotype). Two VS+ V- individuals, with the probable genotype, (C)ce(s)/ (C)ce(s), were homozygous for G733 a nd for T1006. CONCLUSIONS: It is likely that anti-VS and anti-V recogn ize the conformational changes created by Val245, but that anti-V is s ensitive to additional conformational changes created by Cys336.