Pedigree analysis of B el subtype caused by the new allele c.175_176insGA
10.3760/cma.j.cn114452-20240521-00261
- VernacularTitle:新等位基因c.175_176insGA致B el亚型的家系分析
- Author:
Hecai YANG
1
;
Yin GUAN
;
Xiaoli MA
;
Yonglei LYU
;
Yongkui KONG
;
Chaoqun GUO
;
Minglu GENG
;
Liping WANG
;
Tao WEN
Author Information
1. 河南省红十字血液中心血型研究室，郑州 450000
- Keywords:
B el subtype;
Genotype;
Glycosyltransferase;
Protein expression
- From:
Chinese Journal of Laboratory Medicine
2024;47(10):1206-1211
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To serologically and genotypically analyze the pedigree of a case with a new allele c.175_176insGA of B el subtype and preliminarily explore the molecular mechanism of weak expression of glycosyltransferase B. Method:In the descriptive study,a 23-year-old male voluntary blood donor and his family members were selected for the study. The ABO and Le blood types of the proband and his family members was identified by the test tube method. The agglutination inhibition test was applied to detect the B and H antigens in saliva, and the Sanger sequencing and PacBio (Pacific Bioscience) third-generation haplotype sequencing were performed on the study subjects to identify genotypes. Finally, Expasy software were applied to amino acid translation of DNA sequences and prediction of protein length after gene alteration. ORF finder was applied to predict alternative start codons as well as open reading frames of mRNA, and protein expression mechanisms were analyzed.Results:The proband and her sister were B el subtype, her mother was AB el subtype, her father was normal O type, and all members of the family were Le(a+b+) phenotype. Sanger sequencing results showed that a new allele of c.175_176insGA was found in exon 4 of the proband, her mother, and her sister. Third-generation haplotype sequencing detected the haplotypes of the family members, which revealed that the proband was ABO*O.01.02/ABO*BEL.NEW (c.175_176insGA), the father was ABO*O.01.02/ABO*O.01.02, the mother was ABO*A1.02/ABO*BEL.NEW (c.175_176insGA), and the sister was ABO*O.01.02/ABO*BEL.NEW (c.175_176insGA). Analysis of the protein expression mechanism indicated that although the new allele of ABO*BEL.NEW was presumed to cause a frameshift mutation and result in a premature stop codon p.Asp59Glu*fs20 in exon 5, encoding an inactive glycosyltransferase, an alternative start codon could be utilized to initiate translation of B el subtype functional glycosyltransferase. Conclusion:Expression of the new allele of B el subtype is associated with the translation of B el subtype glycosyltransferase initiated by alternative start codons.
