OBJECTIVE: To explore the molecular basis for a rare case with Para-Bombay AB blood type. METHODS: Serological method was used to determine the blood type of the proband. Exons 6 and 7 of the ABO gene and the coding regions of FUT1 and FUT2 genes were analyzed by direct sequencing. RESULTS: Serological results showed that the proband was a Para-Bombay AB subtype. His genotype was determined as ABO*A1.02/B.01. The proband was also found to harbor c.551-552delAG and c.881-882delTT of the FUT1 gene. For his four children, there were three type B and one type A, though the expression of the H type was normal. CONCLUSION The double deletions in the coding region of the FUT1 gene probably underlay the Para-Bombay blood type in the proband. Carrier of single-strand deletions may have a normal ABO phenotype.
ABO Blood-Group System/genetics* ; Alleles ; Fucosyltransferases/genetics* ; Genotype ; Humans ; Male ; Phenotype ; Sequence Analysis