Cataracts, Congenital, Autosomal Recessive 5
Patient Information
Characteristics
Background and History
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.
Clinical Correlations
This is a rare form of cataract having so far been reported in only one family. The parents were second cousins and among their 4 children, three (two boys and a girl) were born with cataracts. Nothing has been reported regarding the appearance of the lens opacities (cataracts) but all of the children were healthy otherwise. Vision was not reported.
Genetics
Inheritance
This is an autosomal recessive condition in which both copies of a gene have been changed (mutated). The parents apparently did not have cataracts but since they each carried one copy of the mutation, they could expect the future children would have a 25% risk of being born with cataracts.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
Diagnosis and Prognosis
The diagnosis is made by an eye doctor. If the cataracts interfere sufficiently with vision, surgery may be indicated. Longevity is likely not impacted.
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