EVIDENCE FOR AUTOSOMAL RECESSIVE INHERITANCE OF A MAJOR GENE FOR BOVINE DILATED CARDIOMYOPATHY

The objective of this study was to establish the mode of inheritance o f bovine dilated cardiomyopathy (BDCMP). We analyzed a pedigree compri sing 75 animals in three age classes and five diagnostic classes based on clinical and pathological findings using the Pedigree Analysis Pac kage. Segregation analyses were performed under three models, a major gene model, a mixed model, and an environment model. Under each model three data sets were analyzed. In the first data set, only animals wit h clinically manifested BDCMP were considered affected; in the second data set, animals with no clinical findings but with strong pathologic al evidence were included in the group of affected animals; and in the third data set, this group was extended to include animals that were suspected of having BDCMP. For all three data sets, a recessive allele at a single biallelic major locus controlling the underlying liabilit y fitted the data best. Based on Akaike's information criterion, the m ajor gene model was the most efficient model in all data sets. We conc lude that a single biallelic major locus is likely responsible for the disease.