MISSENSE MUTATION OF FUT1 AND DELETION OF FUT2 ARE RESPONSIBLE FOR INDIAN BOMBAY PHENOTYPE OF ABO BLOOD-GROUP SYSTEM

The Bombay phenotype fails to express the ABH antigens of ABO blood gr oup system on red blood cells and in secretions because of a lack in a ctivities of the H gene (FUT1)- and Secretor gene (FUT2)-encoded alpha (1,2)fucosyltransferases. In this study, we have examined the FUT1 and the FUT2 from three unrelated Indian individuals with the Bombay phen otype. These three individuals were found to be homozygous for a T725G mutation in the coding region of the FUT1, which inactivated the enzy me activity. In addition, we did not detect any hybridized band corres ponding to the FUT2 by Southern blot analysis using the catalytic doma in of the FUT2 as a probe, indicating that the three individuals were homozygous for a gene deletion in the FUT2. These results suggest that the T725G mutation of FUT1 and the gene deletion of FUT2 are responsi ble for the classical Indian Bombay phenotype. (C) 1997 Academic Press .