A MOTHER-CHILD SEGREGATION DISTORTION FOR THE RH SYSTEM - NEW EVIDENCE FOR ANOTHER COMPATIBILITY SYSTEM ASSOCIATED WITH RH

  • 1 January 1982
    • journal article
    • research article
    • Vol. 34  (6) , 925-936
Abstract
In Santiago, Chile, 6974 mother-infant pairs typed for the D-d alleles of the Rh system were collected. All the pairs that attended from Oct. 1974 to Dec. 1975 and from Jan. 1977 to Sept. 1979 were used. The segregation analysis, made by the T mother-child matrix, assuming Hardy-Weinberg equilibrium, reveals that: Rh(-) mothers have a higher rate of admission than do Rh(+) mothers; Rh(+) mothers produce fewer Rh(-) infants than expected; and, with less significance, Rh(-) mothers produce more Rh(+) infants than expected. This leads to a reduction in the proportion of dd individuals from mothers to their children. Ethnic subdivisions of the sample, the period considered and the extension of the antiisoimmunization therapy do not seem to affect the general pattern of the distortion. Selection is evidently not related to the known Rh antigenic specificities. The reduction of the proportion of dd individuals in 1 generation leads to a review of models on Rh polymorphism. No classical compensation is possible, and d must disappear unless another mechanism maintains it in populations.