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.