3例类孟买血型的分子遗传机制研究

Molecular and Genetic Mechanism of Three Cases of Para-Bombay Blood Group

目的:探讨类孟买血型个体的分子遗传机制。方法:采用常规血清学方法对先证者及其家系成员血液标本进行血型鉴定,对唾液标本进行ABH血型物质的检测;利用PCR扩增3例先证者及家系成员的FUT1基因编码区和ABO血型基因第6、7外显子编码区,对PCR产物进行基因分型和FUT1基因直接测序。结果:3例先证者均为类孟买血型。直接测序结果显示,先证者1的FUT1基因为第328位碱基G/A杂合突变、第547位碱基AG缺失突变的杂合型,FUT1基因分型为h1hnew2杂合;其父亲为单链第547位碱基AG缺失,其母亲为单链328位碱基G/A杂合突变,两者均不是类孟买血型;先证者2和3的FUT1基因为第547位碱基AG缺失突变,第880TT缺失突变的杂合型,FUT1基因分型为h1h2杂合;结论:通过分子生物学技术可以检测FUT1基因不同位点双碱基的缺失杂合和单链缺失突变杂合,进而探讨类孟买血型的分子遗传机制。

Objective： To explore molecular and genetic mechanism of 3 cases of para-Bombay blood group. Methods：The bood samples of proband and family members were selected to identify their blood groups with conventional serologic methods,and salivary components carrying the ABH antigens were detected. The coding regions of FUT1 as well as exon 6 and 7 of the ABO gene were amplified using polymerase chain reaction（ PCR）,and the FUT1 gene was directly sequenced. Results：All the 3 cases of proband were confirmed as para-Bombay blood group. Direct sequencing revealed h new2（ nt328 G→A） and h1（ nt 547 △AG） in FUT1 gene of the proband 1,and FUT1 genotype was h1/h new2. However,the genotypes of his parents were H/h1 and H/h new2,which were non-Bombay individuals. The FUT1 genotypes of proband 2 and 3 were h1 h2（ nt547 △AG） and h1 h2（ nt 880 △TT）,respectively. Conclusion： The technology of molecular biology can be used to detect the base deletion mutations in FUT1 gene,which contributes to the analysis of molecular and genetic mechanism of para-Bombay blood group.