常州地区首例cisAB血型基因特征分析及家系调查

Genetic characteristics and pedigree of the first case of cisAB blood group in Changzhou area

目的研究1例ABO亚型及基因特征。方法采用试管法对家系3代共7例标本进行ABO血型血清学鉴定;对正反定型不一致的标本运用聚合酶链式反应序列特异性引物(polymerase chain reaction-sequence specific primer,PCR-SSP)法基因分型;并对ABO基因第6和7外显子扩增产物进行测序分析。结果ABO血型血清学发现7例标本中正反定型不符3例,其中2例红细胞表型为cisAB/A或ABx,1例为cisAB/O或A2Bx;基因分型为ABO*cisAB01/A101、ABO*cisAB01/O01。ABO基因序列分析:ABO*cisAB01/A101第7外显子发生467C>T、803G>C的特征性突变,ABO*cisAB01/O01第6外显子261位缺失G,第7外显子在467C>T、803G>C存在特征性突变。测序结果均携带有ABO*cisAB01基因。结论ABO*cisAB01基因能导致A抗原或者B抗原的弱表达并能稳定遗传,因此应将血型血清学和分子生物学方法相结合才能准确鉴定ABO亚型。

Objective To study a case of ABO subtype and its genetic characteristics.Methods Tube method was used to perform the serological identification of ABO blood group in 7 samples from 3 generations of one family.Polymerase chain reaction-sequence specific primer(PCR-SSP)assay was used for genotyping the samples with inconsistent positive and negative results.The sequence of exon 6 and 7 of ABO gene was analyzed.Results Among the 7 samples detected,the positive and negative typing of 3 samples was not consistent,and the blood group serological test was different:2 cases showed cisAB/A or ABx,and 1 case showed cisAB/O or A2 Bx.The genotypes were ABO*cisAB01/A101 and ABO*cisAB01/O01.ABO gene sequence analysis revealed that there were 467C>T and 803G>C mutations in exon 7 of ABO*cisAB01/A101,G was missing in 261 ofABO*cisAB01/O01 in exon 6,and there were mutations in 467C>T and 803G>C in exon 7.Sequence analysis displayed thatABO*cisAB01 was detected in all the samples.Conclusion ABO*cisAB01 can induce weak expression of A or B antigens,and can be inherited stably.Blood group serology and molecular biological methods should be combined to accurately identify ABOsubtypes.