Molecular Characterization of FUT1(H) Gene in the Bombay Phenotypes Detected in India

Bombay phenotype, one of the rare blood group was discovered in India in 1952 by Bhende et al. The frequency of this in Western India is about 1 in 7600. Aim  Our Institute gets referral samples from various hospitals and blood banks with problems in grouping and cross matching for identification of blood group and atypical antibodies. We have identified many Bombay phenotype cases out of these by serological procedures. We undertook molecular characterization of FUTI(H) gene on this large series of Bombay phenotypes to see whether the earlier reported mutations on Indian Bombay phenotypes from South Africa and Reunion Island are present in our population or not. Method  Serological confirmations of Bombay phenotypes was done as per standard procedures. Thirty of these serologically confirmed samples were undertaken for molecular characterization of FUTI(H) gene. DNA extraction was done from these samples and FUTI(H) gene was amplified by performing nested PCR followed by digestion with restriction enzyme Nae 1 to screen for T 725 G mutation. The digested product was run on agarose gel electrophoresis and analysed. Result  Out of these 30 samples 27 samples were homozygous for T 725 G mutation and one sample was heterozygous for T 725 G mutation which serologically had shown absence of H antigen on red cells and two samples did not show the presence of this mutation. Conclusion  The T 725 G mutation of FUTI(H) gene appears to be the common mutation amongst the Bombay phenotypes detected in India.