Cohen syndrome is an autosomal recessive disorder, characterized by microcephaly, non-progressive mental retardation, characteristic facial features, neutropenia, and ophthalmologic findings.
Recently, a novel gene, COH1, was shown to carry mutations in many patients with Cohen syndrome.
Chandler et al. (2003) carried out a study that included two consanguineous Arab families with five patients affected with Cohen Syndrome. Haplotype analysis showed allele sharing across the COH1 critical region in the affected patients.
Horn et al. (2000) conducted homozygosity mapping in 2 brothers and a cousin from a multiply consanguineous kindred of Lebanese descent with a syndrome of microcephaly, progressive postnatal growth deficiency, mental retardation, hypotonia, chorioretinal dystrophy, and myopia. They localized the gene responsible for this condition to a 26.8-cM region on chromosome 8q21.3-q22.1.