【多选题】What is the medical consequence when the peroxisomal system for fatty acid catabolism is defective due to genetic mutations?
A.
The peroxisomal system is much more active on very-long-chain fatty acids such as hexacosanoic acid (26:0) and on branched-chain fatty acids such as phytanic acid and pristanic acid. These less-common fatty acids are obtained from dietary intake of dairy products, the fat of ruminant animals, meat, and fish. Their catabolism in the peroxisome involves several auxiliary enzymes unique to this organelle.
B.
The inability to oxidize these compounds is responsible for several serious human genetic diseases. Individuals with Zellweger syndrome are unable to make peroxisomes and therefore lack all the metabolism unique to that organelle.
C.
In X-linked adrenoleukodystrophy (XALD), peroxisomes fail to oxidize very-long-chain fatty acids, apparently due to lack of a functional transporter for these fatty acids in the peroxisomal membrane.
D.
Both defects lead to accumulation in the blood of very-long-chain fatty acids, especially 26:0. XALD affects young boys before the age of 10 years, causing loss of vision, behavioral disturbances, and death within a few years.