Opacities of the lens in the eye (cataracts) can result from a variety of causes such as infections, trauma, and various systemic diseases. Some like this one are inherited as the result of a mutation in a gene.
This form of cataract (lens opacity) is unusual as it is associated with neurological disease in males but not in females. The lens opacification is complete from birth with severe loss of vision in males but only partial in females in whom the vision becomes blurred in the first or second decade of life. Males, but not females, have mental retardation with delayed and slurred speech, and are usually unable to walk or sit unassisted due to weakness and unsteadiness.
This disorder is caused by a mutation on the X chromosome. Unlike other X-linked disorders though, this one causes vision problems in both sexes albeit worse in males. Only males have neurological disease. Carrier mothers with a single mutation on one of their two X chromosomes can be identified by the presence of partial lens opacities. They can expect that half their sons will have cataracts and neurological disease while half their daughters will have only cataracts. Affected males generally are unable to have children.
The diagnosis can be made at birth by an ophthalmologist in males. The full syndrome requires a neurological evaluation as well. Young girls with cataracts only can be diagnosed by an ophthalmologist. Nothing is known about longevity in males but females can expect to live a normal lifespan although they may require cataract surgery at some point in their adult life. There is no treatment for the neurological symptoms but physical therapy may be helpful.