ABCD3 (ATP binding cassette subfamily D member 3) is a peroxisomal ATP-dependent transporter that catalyzes the transport of long-chain fatty acids-CoA, dicarboxylic acids-CoA, and bile acids from the cytosol to the peroxisome lumen for beta-oxidation 1. The protein exhibits fatty acyl-CoA thioesterase and ATPase activities, likely hydrolyzing fatty acyl-CoAs into free fatty acids prior to their ATP-dependent transport into peroxisomes 1. ABCD3 plays a crucial role in regulating long-chain fatty acid metabolism and energy homeostasis through beta-oxidation processes 1. Recent genetic discoveries have identified CCG repeat expansions in ABCD3 (ranging from 118 to 694 repeats) as a cause of oculopharyngodistal myopathy (OPDM) in individuals of European ancestry 2. This represents a novel mechanism where ABCD3 transcript appears upregulated in affected tissues, suggesting that over-expression of CCG repeat-containing ABCD3 transcript contributes to progressive skeletal muscle degeneration 2. The identification of ABCD3 repeat expansions provides diagnostic opportunities for previously unsolved neuromuscular diseases and strengthens the association between CGG•CCG repeat motifs and specific patterns of muscle weakness 23.