Objective: Molecular genetic analysis of FUT1 and FUT2 gene was performed for seven Chinese Han individuals serologically typed as para-Bombay.
Methods: Seven DNA samples were studied by polymerase chain reaction and then by direct sequencing. Molecular cloning sequencing was done for an individual with a novel FUT1 allele. Family segregation analysis of the novel FUT1 allele was done to explore whether the allele was responsible for the fucosyltransferase defects of H.
Results: The FUT1 genotypes of seven para-Bombay individuals were h1h1 (four individuals), h2h2 (two individuals), h328hnew (one individual), alleles h1 lost one of the three AG repeats located at the nucleotides 547-552 of the FUT1 gene, h2 lost two of the three T repeats located at the nucleotides 880-882, h328 (nt328G>A) was a missense mutation, all of them were known mutations, while allele hnew deleted GGTATTCCGCATCACCCTGCCCGTGCTGGCCCC at nt360-400, total 33 bases, and the frame-shift mutation was not previously reported. The segregation of the hnew allele in his family showed that his father genotype was Hh328, and his mother was Hhnew, while two brother were h328hnew. The FUT2 genotypes of seven para-Bombay individuals were Se357 Se357 (three individuals), Se357 Se357,385 (three individuals), Se357,716Se357,716(one individual), the functional Se357(nt357C>T), Se716(nt716G>A) and the weakly functional Se385(nt385A>T) were known. The seven para-Bombay individuals carried at least one copy of a functional FUT2 allele was consistent with their secretor status.
Conclusion: A novel FUT1 allele was identified in a para-Bombay Chinese individual, which was responsible for the inactivation of the FUT1-encoded enzyme activity.