Identification of a Novel FUT1 Allele with c.425G > A on the FUT1*01 Allele Background

The expression of the H antigen on red blood cell membranes is dependent on the human FUT1 gene. We herein report a novel FUT1 allele found in a Chinese individual.

The entire FUT1 genes of these probands were sequenced through PacBio third-generation sequencing. 3D molecular models of the wild-type and mutant fucosyltransferases were generated using the DynaMut web-server. The effect of the mutation on the enzyme function was predicted by PROVEAN and PolyPhen2.

Two probands exhibited discrepancies in their ABO group typing. PacBio sequencing identified that proband 1 possessed a typical ABO*B.01/ABO*O.01.02 genotype for the ABO gene, and was heterozygous with FUT1*01 and a reported functionally weakened allele FUT1*01W.23 (c.424 C > T, p.Arg142Trp) for FUT1 gene. Proband 2 had the ABO*BA.02/ABO*B.01 genotype, and was heterozygous for FUT1*01.02 and a novel FUT1*01-like allele with c.425G > A (p.Arg142Gln). In silico analysis indicated that the c.424 C > T mutation was classified as "Deleterious" or "Damaging", whereas the c.425G > A mutation was considered "Neutral" or "Benign".

We have identified a novel FUT1 allele with c.425G > A on the FUT1*01 allele background in an individual exhibiting the B(A) phenotype. These findings contribute to the expanding repository of knowledge regarding the H blood group system.