RESUMO
To investigate the molecular genetics basis for one para-Bombay phenotype, the red blood cell phenotype of the proband was characterized by standard serological techniques. Exon 6 and 7 of ABO gene, the entire coding region of FUT1 gene and FUT2 gene were amplified by polymerase chain reaction from genomic DNA of the proband respectively. The PCR products were purified by agarose gels and directly sequenced. The PCR-SSP and genescan were performed to confirm the mutations detected by sequencing. The results showed that the proband ABO genotype was A(102)A(102). Two heterozygous mutations of FUT1 gene, an A to G transition at position 682 and AG deletion at position 547-552 were detected in the proband. A682G could cause transition of Met-->Val at amino acid position 228, AG deletion at position 547-552 caused a reading frame shift and a premature stop codon. The FUT2 genotype was heterozygous for a functional allele Se(357) and a weakly functional allele Se(357), 385 (T/T homozygous at position 357 and A/T heterozygous at 385 position). It is concluded that the compound heterozygous mutation--a novel A682G missense mutation and a 547-552 del AG is the molecular mechanism of this para-Bombay phenotype.
