Phenotypes

The double-muscle trait in cattle is characterised by an increase in muscle mass of approx 20%, resulting in substantially higher meat yield, a higher proportion of expensive cuts of meat, and lean and very tender meat, for which a substantial premium is paid. The trait is autosomal recessive, and the locus has been given the symbol mh. It occurs at such a high frequency in Piedmontese and Belgian Blue cattle that it is characteristic of these...

Floriot et al. (2026): "Genetic analysis identified a nonsense variant in the epidermal growth factor receptor (EGFR) gene, XP_002696936:p.Val876Ter, as likely responsible ... ."

The report of the use of a DNA genotyping test by Healy et al. (1995), citing a personal communication from G.S. Johnson at the University of Missouri, implied that the molecular basis of this disorder within the gene for ferrochelatase had been determined by Dr Johnson. Jenkins et al. (1998) appear to have been the first to publicly report the molecular basis of this disorder. They did so by cloning and sequencing a very likely comparative ca...