Retinitis Pigmentosa and Mental Retardation

Clinical Characteristics
Ocular Features: 

The lenses may have pleomorphic white axial opacities but in other patients can be totally opacified.  Optic atrophy is present and vision may be reduced to light perception but nystagmus is absent.  Evidence suggests that vision loss is progressive.  Some patients have extensive posterior synechiae while others have been noted to have sluggish pupils.  High myopia is a feature. The retinal pigmentation has a typical retinitis pigmentosa picture with attenuated retinal vessels and equatorial bone spicule pigmentation located in the midperiphery while the macula can have a bull’s eye appearance.   

Systemic Features: 

Early development may seem normal but developmental milestones are usually delayed.  Postnatal microcephaly and growth deficiency with mental retardation and early hypotonia are typical features.  The mental retardation may be severe.  Scoliosis and arachnodactyly have been noted and hypogonadism has been reported.  Speech may not develop and mobility is sometimes limited.


The family pattern suggests autosomal recessive inheritance.  Homozygosity mapping has identified in a region of chromosome 8 (8q21.2-22.1) that overlaps the region for Cohen syndrome () but no specific mutated gene has been identified.      

Treatment Options: 


Article Title: 


Horn D, Krebsov?deg A, Kunze J, Reis A. Homozygosity mapping in a family with microcephaly, mental retardation, and short stature to a Cohen syndrome region on 8q21.3-8q22.1: redefining a clinical entity. Am J Med Genet. 2000 Jun 5;92(4):285-92.

PubMedID: 10842298

Mirhosseini SA, Holmes LB, Walton DS. Syndrome of pigmentary retinal degeneration, cataract, microcephaly, and severe mental retardation. J Med Genet.1972 Jun;9(2):193-6

PubMedID: 5046629