中国类孟买血型FUT1和FUT2基因研究

Analysis on FUT1 and FUT2 gene of 10 para-Bombay individuals in China

目的 研究中国类孟买血型的 FUT1和 FUT2基因构成。方法 10个血清学初步分析为类孟买血型的标本来源于不同地区 ,ABO常规定型 ,吸收放散试验鉴定其红细胞表面少量 A或 B抗原 ,检测唾液中分泌型血型物质 ,或通过 L ewis血型间接了解其分泌状态。聚合酶链反应 -限制性片段长度多态方法进行 ABO基因分型 ,并与血清学结果相互验证。对 FUT1(H)和 FUT2 (SE)的编码区进行 PCR产物直接测序 ,了解其 H及 SE位点基因型及核苷酸序列组成。结果 血清学和分子生物学两种方法证实 10例皆为罕见的类孟买血型。检测到 h1(nt5 4 7- 5 5 2Δag)、h2 (nt880 - 882Δtt)、h3(nt6 5 8c→ t)和 h4 (nt35 c→ t) 4个FUT1座位上的隐性基因 ,同时发现两种新的隐性等位基因 :hnew- 1 (nt5 86 c→t)和 hnew- 2 (nt32 8g→ a)。 10例中国类孟买个体 FU T2位点的研究表明 ,所有被研究标本的 FU T2基因 ,都具有 nt35 7c→ t的同义突变 ,其中 1例为 Seweak等位基因纯合子。结论 H位点的无效等位基因具有较为广泛的遗传多态性。除了已经报道的 h等位基因外 ,在中国类孟买个体中我们检测到两种新的隐性等位基因 ,并检出 1个 Sew的类孟买个体及 Se基因的一种新的 G716 A单核苷酸多态性位点。

Objective This is a study on the allele composing of ABO, FUT1 and FUT2 gene loci of 10 para-Bombay individuals in China. Methods 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. Results 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(nt547-552Δag), h2h2 (nt880-882Δtt) 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 Bmh (B/O) individual with h4h4 phenotype has a Sew (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. Conclusion Four kinds of known h alleles (h1-h4), 2 kinds of novel non-functional FUT1 alleles, a Sew 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.