Molecular Genetic Analysis of Para-Bombay Phenotype in Chinese: Identification of a Novel FUT1 Allele.

Background: The goal was to identify a novel FUT1 allele and to study serologic and gene feature of the para-Bombay blood type of one expectant mother in Xinjiang, China.

Methods: ABO and Lewis groups were recognized by standard serologic techniques in an ABO typing discrepancy specimen from one person at the Tianjin Blood Center. DNA (deoxyribonucleic acid) was collected and polymerase chain reactions with sequence-specific primers (PCR-SSP) were performed to sequence exons 6 and 7 of ABO gene, exon 4 of FUT1 gene, and exon 2 of FUT2. PCR products were sequenced to identify ABO groups and the variation sites. The genotype was determined by family study.

Results: In our laboratory testing, erythrocytes from the proposita did not react with anti-A and anti-B reagents. B antigen was discovered only after adsorption and elution. Red cells were nonreactive with monoclonal anti-H. The sera of the proposita contained anti-A and were weakly agglutinated by B cells. The hybrid 902 A>G mutation was detected in the proposita's father and mother. The proposita has the same mutation 902 A>G, which was conjectured as homozygosity for 902 A>G.

Conclusions: One novel mutation of FUT1 gene was observed in our laboratory. It has never been reported previously. The para-Bombay phenotype in the proposita originating from Xinjiang (China) results from homozygosity for FUT1 902 A>G, together with 357 C>T of FUT2.