Molecular basis for the RhD negative phenotype in Chinese

Non‐invasive foetal RHD genotyping via real‐time PCR of foetal DNA from Chinese RhD‐negative maternal plasma

“…In Asian populations, RHD ψ is rare, and a certain percentage of RhD‐negative individuals have RHD‐CE‐ D S hybrid gene and RHD 1227A allele. On the other hand, in contrast to Caucasian population, the RhD‐negative blood type only occurs in 0·3–0·5% of the Chinese population [11]; nearly 30% of the RhD‐negative individuals had the RhDel allele, which is a rare variant of the Rh system with a grossly intact RHD gene, of which one is the 1227G>A mutation that probably disrupts normal intron splicing. The RhDel variant D antigen is detectable only by adsorption and elution tests [11].…”

Molecular bases of unexpressed RHD alleles in Chinese D− persons

“…According to previous studies, the D− trait in Chinese individuals could arise from multiple genetic mechanisms 3‐8 . However, a comprehensive study of D− subjects is currently lacking.…”

A DEL phenotype attributed to RHD Exon 9 sequence deletion: slipped‐strand mispairing and blood group polymorphisms

“…Such RBCs phenotype as D– by standard serology and RhD antigen is detected only after adsorbing and eluting anti‐D from these RBCs . More than 40 RHD gene variants associate with the DEL phenotype, the most prevalent being the Asia‐type DEL . Such RBCs have been associated with primary and secondary immunization in D– individuals …”

“…The Asia‐type DEL arises from a single nucleotide change at the RHD gene Exon 9–Intron 9 splice‐site boundary, defined as RHD*1227A . However, the genetic basis for a DEL phenotype among Taiwanese D– donors was initially attributed to RHD Exon 9 deletion . These studies, based on genomic DNA analysis, were never confirmed nor encountered by any other independent group.…”