【摘要】 目的对1名ABO血型正反定型不符的患儿及其家属做ABO血型血清学鉴定和基因检测以弄清原因。方法采用常规血型血清学方法检测患儿ABO血型,以PCR-SSP方法对患儿做ABO基因及ABO血型B亚型基因分型鉴定,并对ABO等位基因直接测序;最后对患儿做家系调查。结果血清学检测:患儿ABO血型为ABx亚型;ABO基因测序并将结果与NCBI网站数据库中ABO血型基因序列比对:患儿除有1个正常的A102基因外,还存在1个未见报道新的点突变型(538C>T)B型变异基因,该位点变异使得基因产物B糖基转移酶第180位氨基酸由精氨酸转变为半胱氨酸,使抗原表达减弱,改变了血型表现型;家系调查:患儿父亲、奶奶、姑姑都拥有相同的新型B变异基因。结论首次在中国汉族儿童中发现1例新的538C>T变异B型等位基因,该B变异基因具有家族遗传性;而且当它与O基因等位共存时,血清学表现型为正常B型,当它与A基因等位共存时,血清学表现出ABx亚型。更多还原

【Abstract】 Objective To investigate the cause of abnormal ABO blood group test results on an infant patient by ABO blood group serological tests and gene sequencing.Methods After routine serological tests with ABO blood group,the ABO gene and ABO blood group-B subgroup genotype were tested by PCR-SSP.Then direct sequencing of ABO alleles was performed,Finally a family survey was conducted to collect additional data for analyses.Results The serological results showed that the child’s ABO blood type is ABx.The gene sequencing result confirmed that the child,apart from a normal allele A101,also possessed an unreported B mutant allele caused by a single locus mutation(nt538 C>T).Such mutation leads to the alternation of arginine to cysteine at the 180 th amino acid site of the product and thus affected its enzyme activity.As for the Family survey,the father,the grandmother and the aunt of the child had the same new B variant allele.Conclusion A novel 538 C> T variant B allele has been found in a Han Chinese child for the first time.Family survey result of the child showeds that 538 C> T point mutant B variant gene has familial inheritance,and when co-existed with O allele,the serotype appears to be a normal B type.When co-existed with A allele,the serotype showes ABxsubtype characteristics.更多还原