Possible linkage between primary affective disorder susceptibility locus and HLA haplotypes

The authors analyzed the concordance of sib pairs of HLA typing in cases where both sibs had affective illness and where the sibs were discordant. They detected an excess of HLA similarities in doubly affected sibs and a lack of similarities in discordant sibs. Therefore, the authors hypothesize that HLA may be linked with a primary affective disorder susceptibility locus or it may be associated with such a locus in some other way.