Maximum likelihood estimation of genetic parameters of HLA-linked diseases using data from families of various sizes

This paper is concerned with estimating parameters associated with HLA-linked diseases. We consider a single disease locus closely linked to HLA, allowing a disease and a normal allele. The parameters to be estimated are the penetrances of the genotypes at the disease locus, the population frequency of the disease allele, and the distance of the disease locus from HLA. The presently used method of estimation uses HLA-sharing information from affected sib-pairs. The method proposed here generalizes the previous approach, using data from all sibs (affected or unaffected) in a family of any size. It allows immediate generalizations to the use of information on parental affectedness status and population prevalence.