Study on a novel mutation of B glycosyltransferase gene related with an ABx variant / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular basis of an individual featuring an ABx variant of ABO blood group system.</p><p><b>METHODS</b>Serological assays were used to characterize the erythrocyte phenotypes and salivary ABH secretors. All of the seven exons and flanking introns of ABO glycosyltransferase gene were amplified with polymerase chain reaction (PCR). And the products were sequenced bidirectionally following enzyme digestion. Exons 6 and 7 were also subcloned and analyzed for haplotypes of the ABO gene.</p><p><b>RESULTS</b>Erythrocytes of the proband have expressed a strong A antigen and a weak B antigen, which was identified as a rare ABx variant in addition with other serological features. Nine heterozygous sites in exon 6 (297A/G) and exon 7 (467C/T, 526C/G, 657C/T, 703G/A, 796C/A, 803G/C, 808T/A, 930G/A) of the coding region of the ABO gene were identified. Based on haplotype analysis, one allele was determined as common A102, whilst another was consistent with B101 except for an 808T>A mutation which has resulted in replacement of phenylalanine with isoleucine at position 270 of glycosyltransferase B.</p><p><b>CONCLUSION</b>The 808T>A mutation of the glycosyltransferase B gene may decrease the enzymatic activity and result in the Bx variant.</p>

Molecular basis for real RhD negative and RhDel phenotypes in Yiwu population of Zhejiang Province in China / 中国实验血液学杂志

This study was purposed to investigate the molecular basis for RhD negative phenotype in Yiwu population in Zhejiang Province of China. The RhD negative samples were screened by saline agglutination test in blood donors. Some real RhD negative and RhDel phenotypes were identified using anti-human globulin test and absorbtion elution test. Ten exons of RHD gene in these samples were amplified by PCR-SSP, and positive exons were DNA sequenced. The results indicated that 30 real RhD negative and 8 RhDel phenotypes were identified in 38 initial RhD negative samples. Ten exons were complete negative in 28 real RhD negative samples and only exon 1, 2 and 10 were positive in 2 real RhD negative samples amplified by PCR. All 10 exons in 8 RbDel samples were positive and a DNA variant (1227G > A) was found in 8 RhDel samples. It is concluded that all exons are absence in most real RhD negative phenotypes, and the partial exons absence is also found in some real negative phenotypes among Yiwu population in Zhejiang province of China. The G to A mutation at position 1227 is found in all RhDel phenotypes.