ABCD1 and Mitchell syndrome: First, related peroxisomal genes such as ACOX1 have been studied in fly models, uncovering a novel human genetic disorder, Mitchell syndrome.28 Also, as previously noted, Abcd2 may compensate in mice, but in flies there is a single Drosophila ortholog Abcd1 (CG2316) for both vertebrate ABCD1 and ABCD2.