ABCD1 and Myelopathy: ,16,17,18,19,20 While the pmp-4-deficient worms and bgm dbb mutant Drosophila highlight axonal damage related to VLCFA and neural degeneration, they are not mammalian models, and the mutations are orthologues of ABCD1. Abcd1-deficient mice, which show elevated VLCFAs in tissue and blood along with myelopathy signs, are commonly used.