The Cohen syndrome. Retinal lesions and granulocytopenia

A patient with the Cohen syndrome is described and the literature is reviewed. Electroretinography (ERG) showed that the patient had a tapeto-retinal degeneration. The authors believe that a retinitis pigmentosa-like phenotype is an obligatory sign in patients with the Cohen syndrome. Assessment of a tapeto-retinal dystrophy by electroretinography, however, is often not available for mentally retarded persons. The authors' patient also had granulocytopenia. This was previously described in Finnish patients with Cohen's syndrome. They speculate that this sign is more prevalent in the disorder than would appear from the literature. Alternatively, there may be a type I Cohen syndrome with granulocytopenia and a type II without.