25 Ahaptoglobinemia in Puerto Rican Newborns

Abstract

Although the frequency of ahaptoglobinemia in the newborn has been determined in Caucasians, little is known about the frequency of this condition in other populations. We are studying ahaptoglobinemia in cord blood specimens from 314 infants born in Puerto Rico, a sample from a heterogeneous population: Caucasian, Negro and mulatto. The frequency of ahaptoglobinemia, as defined by lack of a haptoglobin pattern on starch gel electrophoresis, was found to be 0.777 in 94 samples of the Puerto Rican newborn group studied to date. When this result was compared to the frequencies found in an American-USA (0.873), two southern Italian (0.809 and 0.800) and two Scandinavian (0.767 and 0.900) newborn populations, significant heterogeneity was found in the data (X2(5) = 16.612). Data from the American (USA) and one of the Scandinavian populations account for the heterogeneity; our data do not differ from those of the remaining three Caucasian populations. Ahaptoglobinemia in the Puerto Rican sample was analyzed by studying the effects of several variables. The frequency of ahaptoglobinemia was not affected by sex of the child, birth weight and race of the mother. Parity did not affect the frequency of ahaptoglobinemia, a finding which argues against an isoimmune process as the cause of this condition in the newborn. Finally, no association was found between the frequency of ahaptoglobinemia and the ABO or Rh (D) phenotypes of the infants. These data permit us to tentatively conclude that the frequency of ahaptoglobinemia in the newborn is stable in various populations. Moreover, the data support the contention that ahaptoglobinemia of the newborn represents impaired or absent synthesis of functional haptoglobin. (SPR)