Molecular study on CisAB and B(A) blood group in Chinese individuals / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>This is a study on some ABO subgroup samples which show discordant results of serological and molecular blood typing, the aim is to clarify their true ABO type by means of nucleotide analysis on exons 6 and 7 of their ABO gene.</p><p><b>METHODS</b>Absorb-elution test and family investigation were conducted to study 7 samples which were involved in ABO grouping discrepancies. Duplex polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) method was used to identify their ABO genotypes. PCR products of exons 6 and 7 were cloned and sequenced.</p><p><b>RESULTS</b>All the 7 ABO subgroup samples with the discordant results of serological and molecular blood typing were found to have the normal O gene. Four out of them were typed as ABsub by serology, they were all of the A*102/O genotype. Sequencing analysis found all their A gene having the nt467 (C-->T) and nt803 (G-->C) mutation by comparison with the A*101 allele, i.e. their real type should be CisAB/O. Three out of 7 were typed as AsubB by serology and as BO by genotype; and point mutation was detected in all of their B gene. One of them had the nt700 (C-->G) mutation, the other 2 unrelated individuals had the novel nt640 (A-->G) mutation in their B alleles.</p><p><b>CONCLUSION</b>Through nucleotide analysis, 7 samples have been typed as AB subgroup in serology with the normal O gene, their real ABO type being CisAB in 4 cases and B(A) in 3 cases. At the same time, a kind of novel B (A)640 allele has been uncovered in this study.</p>

Analysis on FUT1 and FUT2 gene of 10 para-Bombay individuals in China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>This is a study on the allele composing of ABO, FUT1 and FUT2 gene loci of 10 para-Bombay individuals in China.</p><p><b>METHODS</b>Ten samples coming from different districts of China were suspected of para-Bombay phenotype by primary serology tests. Routine and absorb-elution tests were conducted to identify their ABO type, and duplex polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was applied to getting their ABO genotype. Most of them were submitted to a test of their Lewis type as well. Then through direct DNA sequencing with PCR products of FUT1 and FUT2 genes, the genotypes of their H and SE gene loci were analyzed.</p><p><b>RESULTS</b>It can be confirmed that the 10 samples are para-Bombay. All of their ABO genotypes are consistent with the serological absorb-elution results and the substances detected results in saliva. Seven out of 10 have recessive homozygous gene at their H locus. Each phenotype of h1h1 (nt547-552Deltaag), h2h2 (nt880-882Deltatt) and h4h4 (nt35 t-->c) are ascertained in 2 individuals; moreover, h3h3 (nt 658 c-->t) is identified in one individual. The rest are hh heterozygous individuals: one is h3/h(new-1); the other is h2/h(new-2); the last one is h1/h2. The h(new-1) (nt586 c-->t) allele has a point mutation at nt 586 C to T, which leads a nonsense mutation Gln(CAG) to stop (TAG).The second h (new-2) (nt328 g-->a) has an nt328 G to A missense mutation,which leads Ala (GCC),was replaced by Thr (ACC) at 110 amino acid position. All the 10 samples have Se (nt357 c-->t) synonymous mutation. One Bm(h) (B/O) individual with h4h4 phenotype has a Se(w)(nt357 c-->t; nt385 a-->t) allele, whose Lewis type is Le(a+b+). Moreover, the authors detected a (nt716 g-->a) mutation in two samples' Se gene.</p><p><b>CONCLUSION</b>Four kinds of known h alleles (h1-h4), 2 kinds of novel non-functional FUT1 alleles, a Se(w) allele, and a novel SeG716A polymorphism in Chinese para-Bombay individuals were detected. At the same time, the authors noticed that all the 10 samples have the nt357 c-->t mutation in their FUT2 gene.</p>