What causes ALD Disease?
ALD Disease is one of several inherited disorders where the myelin sheath – the fatty insulating layer that covers many of the neurons – is progressively damaged, because of a faulty gene. Without the myelin sheath the nerves don’t work as they should.There are several different types of ALD Disease, which may be inherited in two different ways. ALD Disease is most commonly inherited as an X-linked condition. This means the abnormal gene is found on the X chromosome. Because women have two X chromosomes, they have a spare normal gene as well as the abnormal one, so they generally only carry ALD Disease. But men have only the one faulty X, so they are affected by the condition. X-linked ALD Disease may occur in three forms, with onset of symptoms in either childhood or in adulthood. Neonatal ALD Disease is much less common. In this type of ALD Disease the faulty gene is not X-linked but found on one of the other chromosomes, so both boys and girls can be affected.
