Bombay Phenotype

 Bombay Phenotype is a rare genetic trait that originally started in Bombay , are hh individuals that failed to produce substance H (antigen H) which is needed for the adhesion of antigens A and B sugars on the surface of red blood cells. Individuals with Bombay Phenotype most likely have either blood type "A", "B" or "AB", however due to the lack of antigen H, their blood type is expressed as "O" when a quick blood test is run.