Adrenoleukodystrophy (ALD) is a rare genetic disorder that causes the breakdown of myelin. This disease is due to a mutation of a sex-linked chromosome and mainly affects boys. Once symptoms appear, an affected boy quickly loses his ability to hear, see, speak, or move, and may die within two years.
The normal version of this gene codes for a transport protein that moves fatty acids into peroxisomes, where they are metabolized. Without these transporter proteins, certain fatty acids build up in the cells. This buildup likely causes the inflammation and demyelination of axons that occur in the central nervous system.
Some fatty acids are introduced into the body through diet, and others are synthesized by the body. Therefore, one way to delay progression of this disease is to eliminate consumption of these fatty acids. It is also possible to slow the synthesis of fatty acids. Lorenzos Oil, a mixture of olive and rapeseed oils, can interfere with the body’s ability to synthesize the fatty acids whose buildup causes ALD. A recent study found that 76% of boys with the mutant transport protein associated with ALD but no symptoms still produced normal brain scans after 10 years of taking Lorenzos Oil. Only 33% of the boys who did not regularly take the oil remained free of the symptoms of ALD after 10 years.
Explain how degeneration of the myelin sheath could cause the symptoms of ALD.