Background: A case of a para-Bombay phenotype caused by a compound heterozygous mutation in the FUT1 gene was identified in this study.
Methods: We performed an agglutination examination of anti-H serum and secretor status to assess the presence of soluble blood group substances. Genotyping of ABO and FUT1 genes was also performed.
Results: Our results showed the presence of A and H antigens in saliva. Based on these results, the patient in the present case was diagnosed with the para-Bombay A phenotype. Direct DNA sequencing of the ABO gene indicated A1v/O1vgenotype. FUT1 gene sequence analysis revealed that the patient harbored the compound heterozygous mutation, c.881_882delTT (p.Phe294Cysfs*40) and c.658C>T (p.Arg220Cys).
Conclusions: Improper identification of this phenotype may cause inappropriate transfusions because this particular blood group may be mislabeled as group O. Therefore, blood bank staff should be well trained to solve the discrepancy between cell and serum grouping in the para-Bombay phenotype.