Adrenoleukodystrophy is caused by what deficiency of a protein in the outer membrane of?

Adrenoleukodystrophy (ALD) is caused by a deficiency of the ABCD1 protein, which is located in the peroxisomal membrane. This protein is responsible for the transport of very long-chain fatty acids (VLCFAs) into peroxisomes for degradation. The deficiency leads to the accumulation of VLCFAs in the body, particularly in the adrenal glands and nervous system, resulting in the various symptoms associated with the disorder.