Figure 9. Overview of metabolic rerouting in ALD.

(A) ALD is caused by mutations in the ABCD1 gene that produces the ABCD1 protein, a transporter of VLCFAs from the cytosol into the peroxisomes. A deficiency in ABCD1 blocks this transport, which results in impaired degradation and a subsequent buildup of VLCFAs in cells, tissues, and organs. (B) VLCFAs are synthesized through LCFA elongation largely controlled by ELOVL1. Activation of SCD1 causes a shift from the saturated toward the monounsaturated fatty acids.