Bombay phenotype in two North Indian brothers: a case report.

ABSTRACT

Bombay phenotype is unique in the aspect that the red cells are not agglutinated by antisera A, B and H. However the serum of such individuals contains anti A, B and strongly reactive anti H which agglutinates red cells of 'O' group individuals through a wide thermal range. The blood specimen of a 35 year old male donor who donated blood for the first time was subjected to detailed cell and serum grouping. There was a discrepancy between the results. The possibility of Bombay phenotype was considered and the sample was tested with anti H lectin. Further confirmation of blood group and secretor status was done from a reference laboratory. Family studies showed the same blood group in the elder sibling of the propositus. The present case highlights the significance of correlating cell and serum grouping results. Moreover, this blood group is very rare in North India. Family studies revealed the propositus to possess the B gene which was suppressed in the donor but expressed in the offsprings. The use of anti H in discrepant blood grouping results is recommended.