Four Non-functional FUT1 Alleles Were Identified in Seven Chinese Individuals with Para-Bombay Phenotypes.

Background: The para-Bombay phenotype is characterized by a lack of ABH antigens on red cells, but ABH substances are found in saliva. Molecular genetic analysis was performed for seven Chinese individuals serologically typed as para-Bombay in Blood Station Center of Ningbo, Zhejiang Province, Ningbo, China from 2011 to 2014.

Methods: RBCs' phenotype was characterized by standard serologic technique. Genomic DNA was sequenced with primers that amplified the coding sequence of α (1, 2)-fucosyltransferase genes FUT1 (or H ) and FUT2 (or Se ), respectively. Routine ABO genotyping analysis was performed. Haplotypes of FUT1 were identified by TOPO cloning sequencing. Phylogenetic tree of H proteins of different organisms was performed using Mega 6 software.

Results: Seven independent individuals were demonstrated to possess the para-Bombay phenotype. RBC ABO genotypes correlated with ABH substances in their saliva. FUT1 547delAG ( h1 ), FUT1 880delTT ( h2 ) , FUT1 658T (h3) and FUT1 896C were identified in this study. FUT1 896C was first revealed by our team. The H -deficient allele reported here was rare and the molecular basis for H deficient alleles was diverse as well in the Chinese population. In addition, the FUT2 was also analyzed, only one FUT2 allele was detected in our study: Se357 . Phylogenetic tree of the H proteins showed that H proteins could work as an evolutionary and genetic marker to differentiate organisms in the world.

Conclusion: Molecular genetic backgrounds of seven Chinese individuals were summarized sporadic and random mutations in the FUT1 gene are responsible for the inactivation of the FUT1 -encoded enzyme activity.