Para-Bombay phenotype: A case report from a tertiary care hospital from South Gujarat

The blood specimen of a 30-year-old male donor showing a discrepancy in cell and serum grouping was targeted for detailed study at the blood bank at tertiary care hospital in South Gujarat. Forward grouping showed group as “O” RhD positive and reverse grouping as group “A.” Further testing confirmed that the individual's blood group was para-Bombay A (para-AH). Family members were screened, and younger brother was also identified as para-Bombay phenotype. The para-Bombay phenotype is very rare, and only a few cases have been reported from India. This blood group is characterized by the absence of ABH antigens on red blood cells (RBC's) with the presence of ABH substances in body secretions or by the weak expression of ABH antigens on RBC's with the absence or presence of substances in body secretions. This rare phenotype can be mislabeled as “O” if all detailed investigations are not performed.