Background: The para-Bombay phenotype results from a variety of mutations in the α-(1,2)-fucosyltransferase gene (FUT1). We investigated samples from seven Chinese probands serologically typed as having the para-Bombay phenotype.
Materials and methods: The para-Bombay phenotype was identified by standard serological methods. Genetic mutations of FUT1 and FUT2 genes were analysed by DNA sequencing. Heterozygous mutations of FUT1 were identified by TOPO cloning sequencing. Blood samples from 331 randomly-selected Chinese donors were analysed with the SNaPshot system to distinguish five known mutations (Se C357T, A385T, G428A, G716A and FUT1 880delTT) in the FUT1 and FUT2 genes. The genetic characteristics of all para-Bombay probands identified in the Fujian Blood Centre, including those in the present study, were also summarised.
Results: Three FUT1 genotypes, h1/h1 (5 individuals), h1/h6 (1 individual) and h3/h2 (1 individual), and three FUT2 genotypes, Se(357)/Se(357) (5 individuals), Se(357)/Se(357, 385) (1 individual) and Se(357)/Se(357, 716) (1 individual) were observed in seven para-Bombay probands. Among 331 donors, only one individual carried the G716A and 880delTT mutations in heterozygosity; this subjects FUT1 and FUT2 genotypes were H/h2 and Se(357)/Se(357, 716), respectively.
Conclusion: The review of all para-Bombay probands identified in the Fujian Blood Centre showed that h1 and h2 are the predominant non-functional FUT1 alleles in Fujian para-Bombay individuals. Our data confirm the hypothesis that the h2 allele is linked to Se(357, 716), and the concurrence of unique FUT1 and FUT2 mutations is geographically specific.