Incongruent parenthood in a Mexican mestizo population as determined by HLA typing

The incidence of incongruent parenthood was determined by confronting the declared familial relationship of 98 father-mother-son/daughter trinomials (drawn from the Centro Médico Nacional-IMSS (CMN-IMSS) Kidney Transplant Program) with their HLA-A and B antigens. Fourteen (14.3%) discrepant cases were found: three each with the putative father (3.1%) or with the putative mother (3.1%), two with either father or mother (though impossible to determine precisely with whom) (2.0%), and six with both parents (6.1%). Several possible explanations of these findings were considered, such as out-of-wedlock pregnancies, complex known or unknown, declared or undeclared social circumstances frequently related to the population studied (i.e. imminent kidney transplantation) and technical pitfalls. These data underscore the level of possible "noise" and imprecision in population genetics; genetic-epidemiology and transplantation programs.