D(Va) category phenotype and genotype in Japanese families.

BACKGROUND AND OBJECTIVES: The genetic background of the D(Va) category phenotype has been described in two Caucasian individuals. We were interested in the RHD sequence of 7 Japanese D(Va) individuals and their families. MATERIALS AND METHODS: With SSP-PCR we tested exons 4, 5 and 7 of the RHD gene and used restriction enzymes for testing nucleotide associated with the D(Va) phenotype. RESULTS: A single RHD G667 C697 allele was present in 5 individuals with D(Va) category phenotype, and in 2 individuals we found a D-CE-D hybrid gene (exon 5 had been replaced). The D(Va)Ce gene complex was found in all families. CONCLUSION: The changes of the RHD gene described in European D(Va) individuals were also observed in Japanese families.