HACD1 and congenital myopathy with cores: Deficiency in HACD1 function disrupts lipid-dependent growth mechanism, leading to impaired myoblast fusion, myofiber hypotrophy, and generalized muscle weakness [20], which is evidenced in Hacd1-knockout models and is associated with congenital myopathies characterized by fiber size disproportion in both humans and dogs [19,21].