Congenital malformations, deformations and chromosomal abnormalities
Other congenital malformations
Autosomal recessive
8q22.2
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.
| Subject ID | Country | Sex | Family History | Parental Consanguinity | HPO Terms | Variant | Zygosity | Mode of Inheritance | Reference | Remarks |
|---|---|---|---|---|---|---|---|---|---|---|
| 216550.1.1 | Oman | Female | Yes | Yes | Microcephaly; Global developmental dela... Microcephaly; Global developmental delay; Myopia; Retinopathy; Narrow foot; Narrow palm; Joint hypermobility;  | NM_017890.4:c.7934G>A | Homozygous | Autosomal, Recessive | Hennies et al. 2004 | Sibling of 216550.1.... |
| 216550.1.2 | Oman | Male | Yes | Yes | Microcephaly; Global developmental del... Microcephaly; Global developmental delay; Myopia; Retinopathy; Narrow foot; Narrow palm; Joint hypermobility; | NM_017890.4:c.7934G>A | Homozygous | Autosomal, Recessive | Hennies et al. 2004 | Sibling of 216550.1.... |
| 216550.1.3 | Oman | Male | Yes | Yes | Microcephaly; Global developmental de... Microcephaly; Global developmental delay; Myopia; Retinopathy; Narrow foot; Narrow palm; Joint hypermobility; | NM_017890.4:c.7934G>A | Homozygous | Autosomal, Recessive | Hennies et al. 2004 | Sibling of 216550.1.... |
| 216550.2.1 | Saudi Arabia | Female | Yes | Yes | Microcephaly; Retinal dystrophy; Myopi... Microcephaly; Retinal dystrophy; Myopia; Abnormal length of corpus callosum; Inferior cerebellar vermis hypoplasia; | NM_152564.5:c.1219C>T | Homozygous | Autosomal, Recessive | Mochida et al. 2004 | Sibling of 216550.2.... |
| 216550.2.2 | Saudi Arabia | Male | Yes | Yes | Microcephaly; Inferior cerebellar verm... Microcephaly; Inferior cerebellar vermis hypoplasia; | NM_152564.5:c.1219C>T | Homozygous | Autosomal, Recessive | Mochida et al. 2004 | Sibling of 216550.2.... |
| 216550.2.3 | Saudi Arabia | Female | Yes | Yes | Microcephaly; Microcephaly; | NM_152564.5:c.1219C>T | Homozygous | Autosomal, Recessive | Mochida et al. 2004 | Sibling of 216550.2.... |
| 216550.3.1 | Palestine | Male | Yes | Yes | Exotropia; Retinal dystrophy; Optic di... Exotropia; Retinal dystrophy; Optic disc pallor; Visual impairment; Abnormality of refraction | NM_017890.4:c.1225G>T | Homozygous | Autosomal, Recessive | Taban, 2007 | Patient 'A1' in the ... |
| 216550.3.2 | Palestine | Female | Yes | Yes | Retinal dystrophy; Esotropia; Bilatera... Retinal dystrophy; Esotropia; Bilateral ptosis; Tapered finger; Truncal obesity; Optic disc pallor; Abnormality of refraction | NM_017890.4:c.1225G>T | Homozygous | Autosomal, Recessive | Taban, 2007 | Patient 'A2' in the ... |
| 216550.3.3 | Palestine | Female | Yes | Yes | Retinal dystrophy; Bilateral ptosis; O... Retinal dystrophy; Bilateral ptosis; Optic disc pallor; Abnormality of refraction | NM_017890.4:c.1225G>T | Homozygous | Autosomal, Recessive | Taban, 2007 | Patient 'A3' in the ... |
| 216550.4.1 | Syria | Male | Yes | Retinal dystrophy; Optic disc pallor; ... Retinal dystrophy; Optic disc pallor; Abnormality of refraction | NM_017890.4:c.6530_6732del | Homozygous | Autosomal, Recessive | Taban, 2007 | Patient 'B1' in the ... |
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.