一例ABw03亚型的全编码区测序及家系分析

Whole exome sequencing and pedigree analysis for a case with an ABw03 subtype

目的分析1例ABO亚型献血者及其家系的血清学检测结果和ABO血型基因型,探讨ABW03亚型的家系遗传规律。方法用血清学方法检测先证者及4名家族成员的ABO血型,用荧光PCR法和全编码区测序对5例标本进行基因分型和序列分析。结果先证者血型符合ABw亚型的表型特征。根据基因分型和测序结果推测先证者基因型为A102/BW03。ABO*BW.03等位基因与ABO*B.01相比,第7外显子存在721C>T变异,导致241位精氨酸被色氨酸替换,表型为ABw。先证者妹妹血型与先证者一致。其母亲血清学格局为B型,基因分型和测序结果推测其基因型为B101/BW03型。结论ABO糖基转移酶基因第7外显子721C>T变异为BW03亚型典型变异。先证者及妹妹的ABO*BW.03基因遗传自母亲,符合家系遗传的特点。

Objectives To explore the molecular basis for a blood donor with an ABO subtype. Methods The proband and his family members were subjected to serological analysis. Their genotypes were determined by real-time PCR and sequencing of the coding regions of ABO gene. Results The proband was determined as an ABw subtype. By sequencing analysis, the proband was typed as A102/BW03. Compared with ABO*B.01, the proband was found to harbor a 721C>T variant (ABO*BW.03 allele) in exon 7 of the ABO gene, which caused substitution of Arginine at position 241 by Tryptophan resulting in a ABW phenotype. The blood type of the proband’s sister was similar to that of the proband. The maternal serological pattern was B type, and the result of sequencing suggested that the genotype fit with B101/Bw03. Conclusion The 721C>T in the exon 7 of the ABO glycosyltransferase gene probably underlies the Bw03 phenotype. The ABO*Bw.03 variant of the proband and his sister were inherited from their mother.