HLA study of 21 families with two or more members affected by febrile convulsions.

21 Italian families with at least two members who had had febrile convulsions (FC) were HLA-typed for class I antigens. A total of 49 subjects and 43 close relatives (parents or sibs) were examined. No single antigen or haplotype was statistically more frequent among pooled FC subjects. The study, however, is not conclusive regarding a relationship between FC and HLA region because of the possible genetic heterogeneity of proneness to FC. In a significant proportion of cases two FC affected sibs had unaffected parents: besides the models of inheritance so far proposed for this pathology, the involvement of two complementary dominant factors was also considered. The report includes uncommon cases: a family where one FC affected parent transmitted the same HLA haplotype to all three affected sibs; two more families, with both parents and progeny affected by FC. The HLA typing of all members of these unusual families, although not furnishing relevant information at present, may be of value to other investigators.