OMIM ID:
Cataracts, Congenital, Autosomal Recessive 2
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Bilateral nuclear lens opacities are either present at birth or noted during infancy. The cataracts were sufficiently dense that surgery is necessary within several months of age in most patients. No other ocular disease is present.
Systemic Features
No systemic abnormalities are present.
Genetics
Inheritance
CATC2 is an autosomal recessive condition that has been reported in 12 consanguineous Pakistani families. Homozygous mutations in FYCO1 (3p21.31) segregated with the lens opacities as expected. Mutations in FYC01 are among the most common causes of congenital cataracts in Pakistan and may account for about 10% of the total genetic load of cataracts in this country. Mutations in the same gene have been found segregating in several consanguineous Arab families with congenital cataracts as well.
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.