摘要目的 分析主要组织相容复合物I类相关基因A(rnajor histocompatibility complex class Ichain-related gene A,MICA)无效等位基因MICA* 063N的核苷酸序列及探讨其分子基础.方法 采用直接测序法(sequence-based typing,SBT)对MICA* 063N基因进行多态性分析并应用基因克隆测序法检测其碱基序列,应用测序软件比对MICA分型.结果 直接测序法发现该基因序列与MICA* 027类似,在第2外显子编码子62碱基位置184出现信号“Y”,提示该位置出现碱基突变.再以克隆测序法证明,该碱基突变为C→T,在该位置编码子由CAG→TAG,TAG编码终止密码子.由于该等位基因提前出现终止密码子,因此推测可能该基因表达为截短或无效蛋白质.结论 MICA* 063N基因序列已提交GenBank,已于2010年10月获世界卫生组织HLA命名委员会正式命名(编号HWS10011131).

abstracts[Objective]To analyze the full nucleotide sequence of a null allele of major histocompatibility complex class I chain-related gene (MICA).[Methods] A sequence-based typing method was used to determine the nucleotide sequence of the MICA gene.Potential alleles were identified with a computer program.[Results] The identified allele has possessed a sequence similar to that of MICA * 027 except for a C→T substitution at position 184 in codon 62 (CAG→TAG) of exon 2.As a stop codon,this may result in a truncated protein.[Conclusion] A null allele of MICA gene has been identified.The sequence has been submitted to the Genbank nucleotide sequence database (submission No.HWS10011131),which was officially named as MICA * 063N by the WHO Nomenclature Committee in October 2010.