Blood samples from 577 couples and their 657 offspring of Bengali cast
e group derivation were used to study interactions between ABO blood g
roups and haptoglobin (HP) systems. There was no significant sex diffe
rence in HP distribution among the parents. Significantly higher incid
ences of HP1 allele were noted in the off-spring of ABO-incompatible
parental combinations in comparison with those in the offspring of ABO
-compatible parents.