Cataracts, Congenital, Intellectual Disability, Abnormal Striatum, and ADHD
Defective Genes
Clinical Characteristics
Ocular Features
Cataracts (not further described) were described as congenital although the diagnosis was usually made early in the first decade of life. One patient was diagnosed at the age of 8 years with glaucoma and a cloudy cornea of the left eye. Another patient had cataract surgery. Visual acuities have not been reported.
Systemic Features
Four members of a consanguineous Saudi family have been reported with growth and mental retardation, microcephaly, dystonia, and spasticity. IQs in the range of 77-89 were reported. Linguistic delay is common. Dysarthria and decreased cognitive function are present. MRIs revealed thinning of the lentiform nucleus and swelling of the caudate heads.
Genetics
Inheritance
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.