Testing genetic models for IDDM by the MASC method

The MASC method has been applied to the GAW5 data. The method uses the simultaneous information on association and segregation of the HLA marker with the disease and the segregation of the HLA marker in affected families. It also takes into account the differential risk for parents of a patient, as well as the different HLA haplotype sharing, according to the HLA genotype of the patient. The goodness of fit of several genetic models has been tested. The observed data are not compatible with a two-allele, one-locus model, but they fit a three-allele, one-locus model and a complementation two-locus model if additional familial correlation is allowed.