TRIM39 and cardiomyopathy: Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and trifunctional protein (TFP) deficiencies can present with serious, rapidly progressive cardiomyopathy, hypoketotic hypoglycemia and liver dysfunction, and rhabdomyolysis, among other manifestations.1 Almost all cases of isolated LCHAD deficiency are caused by a c.1528G>C variant of the HADHA gene encoding the α subunit of TFP.