No abstract

Six families with familial malignant melanoma (FMM) were HLA-A, -B, and -C typed to ascertain whether or not FMM would segregate with the HLA complex. The HLA-B12 antigen was present in five of the six families. In three families the HLA-FMM linkage could be analyzed: linkage was possible in two but not in the third. These findings suggested that two types of FMM may exist: a more frequent type (five cases) that apparently segregates with the HLA complex and another (one case) that does not segregate with the HLA complex. Moreover, a factor included in the HLA region or another factor linked to it may have played an important role, in five of the six families, in FMM pathogenesis, whereas in the sixth family its role may have been performed by some other factor. These findings are consistent with the hypothesis of two complementary factors (one of which was included in the HLA complex) for the promotion of FMM with dominant inheritance and high penetrance.

No abstract

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.

No abstract