Molecular basis of weak D in Taiwanese

Abstract

Two genes, RHD and RHCE, encode the antigens of the RH blood group system. The weak D phenotype is caused by many different RHD alleles encoding aberrant RhD proteins, resulting in distinct serologic phenotypes and anti-D immunization. We analyzed seven weak D phenotypes excluding D(el), using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing methods to detect the changes of all ten RHD exons. The results show that there are four types of weak D in Taiwanese: one case each for CGG to CAG mutation at codon 10, GTG to ATG mutation at codon 174, and GTG to GAG mutation at codon 270, and four cases for GGT to GAT mutation at codon 282. In conclusion, we present the first data of a molecular basis of weak D in Taiwanese, which suggest a clinically relevant potential for anti-D immunization and may improve transfusion strategy in weak D Taiwanese patients.

Diverse and novel RHD variants in Australian blood donors with a weak D phenotype: implication for transfusion management

“…The improved resolution in RHD genotyping strategy has allowed a diverse array of RHD variants beyond RHD*weak D type 1, RHD*weak D type 2 and RHD*weak D type 3 to be defined. This included East Asianassociated RHD variants such as RHD*weak partial 15 and RHD*weak D type 33, and African-associated variants such as RHD*weak partial 4Á0, RHD*weak partial 4Á1 and RHD*weak D type 90 [7,[22][23][24][25][26][37][38][39]. It also included a novel RHD*c.939+3A>C variant that had exhibited a nucleotide substitution in Intron 6 and a weak partial D-epitope profile lacking epD1Á2.…”

“…Weak D types 4Á0 and 4Á1 have been reported as frequently occurring alleles in African populations from Egypt, Tunisia, Ethiopia and South Africa [7,21,22]. Weak D type 15 and 33 predominate in East Asian donor populations from Japan, China and Taiwan [23][24][25][26]. In 2000, a study of 99 Australian blood donors with a weak D phenotype showed the majority of RHD variants comprised weak D types 1, 2 or 3 (n = 88), similar to those reported in Europe and Canada [27].…”

Red blood cell genotyping in China

“…To date, at least 27 weak D alleles and 14 partial D alleles have been identified in the Chinese population (Tables and ), which are low compared with the hundreds found in the Caucasian population. RHD*weak partial 15 and RHD*DVI.3 are the most common D variant alleles, accounting for more than 70% of D variants in the Chinese population.…”

“…To date, at least 27 weak D alleles [43,46,47,[58][59][60][61][62][63]] and 14 partial D alleles [46,57,58,61] have been identified in the Chinese population (Tables 2 and 3), which are low compared with the hundreds found in the Caucasian Xi'an [46] (n = 72) Shenzhen [43] (n = 3)…”

Application of a Multivariant, Caucasian-Specific, Genotyped Donor Panel for Performance Validation of MDmulticard^®, ID-System^®, and Scangel^® RhD/ABO Serotyping

“…It was in 1999, when Wagner et al [6] described the molecular basis of weak D phenotypes, hereby opening the way for the unambiguous definition and typing of every single 'D u ' sample. Shortly thereafter an impressive number of articles described the frequency of weak RHD alleles found in sample collections of phenotypically weak Ds analyzed in a variety of populations [7][8][9].…”