D^Va Category Phenotype and Genotype in Japanese Families

Abstract

The changes of the RHD gene described in European D(Va) individuals were also observed in Japanese families.

Molecular basis of D variants in Chinese persons

“…Together with the findings of Lan and coworkers, Shao and coworkers, Lin and coworkers, and others, 13‐25 our results contribute to increasing knowledge of the differences in the molecular genetics and expression of the D antigen among Asian, European, and African populations 1‐11,13‐25,30 . It also confirms that “weak D” is not a single D u , but weak Ds, a heterogeneous group of D peptides, frequencies of which depends on the typing methods, serologic cutoff, and affinity of anti‐D 11,29,32 .…”

“…Also, in the absence of standardized typing reagents and serologic methods for detecting D– and D variant phenotypes, any comparison of gene or phenotype frequencies between various populations and/or published studies must be made with considerable caution. Nevertheless, we believe that our results, together with others, 13‐25 indicate that the prevalence and molecular basis of D variants in indigenous Chinese are significantly different from those in European and African populations 1‐11 …”

“…The results of our study confirm the considerable polymorphism of RHD among indigenous Chinese and identify three new alleles associated with the weak D phenotype. Although two of three new alleles were detected from D‐weakly positive samples, which probably had been excluded from the investigation by the previous studies, 13‐15 all other eight alleles had been observed in six previously conducted studies focusing on Chinese and Japanese populations 13‐15,19‐21 . Weak D Type 15 and DVI Type 3 constituted 35 and 22 percent of the 32 D variants detected, which suggests they are the major weak D and partial D alleles in Chinese.…”

“…One allele with 667T>G and 697G>C mutations on exon 5 was typical of DV Type 1, 4,20,29 another allele associated with 667T>G, 676G>C, 697G>C, 712G>A, 733G>C, 744C>T, 787G>A, and 800A>T mutations was classified as DV Type 2 4,15,29 . A third allele representing 667T>G, 676G>C, 697G>C, 712G>A, 733G>C, and 744C>T mutations was typical of DV Type 8 21,29 .…”

“…Studies of D variant phenotypes in Caucasian and African populations have provided considerable information about their frequency and molecular characteristics 1‐12 . Relatively few studies of RHD alleles have been conducted among Asians and, in particular, indigenous Chinese 13‐21 . Except for certain focused analysis of Rh phenotypes or haplotypes in specific geographic or ethnic populations, molecular research of the Rh blood group system in indigenous Chinese has been limited to gene structure analysis and genotyping by polymerase chain reaction with sequence‐specific primers (PCR‐SSP) 22,23 .…”