Identification of a novel FUT1 allele with two mutations in a Chinese para-Bombay individual

Background: The para-Bombay phenotype often results from a silenced β-D-galactoside 2-α-fucosyltransferase 1 (FUT1) gene (h/h) but an active FUT2 (Se/Se or Se/se) gene. We identified a para-Bombay phenotype with two novel mutations in the FUT1 gene and homozygous mutated FUT2 (se^{357, 385} /se^{357, 385} ) genes.

Study design and methods: Red blood cell phenotype was detected by using a standard serologic technique. The entire coding regions of the FUT1 and FUT2 genes were amplified and direct sequenced using genomic DNA.

Results: No ABH substance was detected on the surface of the proband's red blood cells. Anti-A, anti-B, and anti-H were identified in serum. Genetic studies indicated that the proband's ABO genotyping was A102/O01 and that the FUT2 phenotype was se^{357, 385} /se^357,385 . The sample was homozygous for two FUT1 mutations: c.958insG and c.961G > A.

Conclusion: Two novel FUT1 mutations have been identified in the proband's FUT1 gene. The insertion mutation in the FUT1 that caused a shift of the open reading frame and formed a termination codon early at Amino Acid Position 334 may be the main reason for H deficiency in this case.