Cohen syndrome

Page most recently updated 7 September 2026

This page focuses on the reported psychiatric associations, which may be the initial presenting manifestation, and on other clinical features that may assist the psychiatrist or primary care physician in identifying the underlying diagnosis, considered through the lenses of the diagnostic lenses framework.

Cohen syndrome is a rare genetic condition. It is an autosomal recessive genetic condition, so affected individuals typically have unaffected parents and there may be no relevant family history. A distinctive presentation may include the combination of acquired microcephaly (progressive reduction in head growth relative to age), truncal obesity developing in later childhood or adolescence, progressive high myopia with retinal dystrophy, neutropenia, and intellectual impairment with a cheerful and friendly demeanour.

It can present with psychiatric features such as ADHD, anxiety, autism spectrum disorder (ASD), aggression and self-injurious behaviour. A cheerful and friendly disposition is characteristic, while maladaptive and autistic-type behaviours have also been described. Aggression and self-injury have been reported, particularly in adults. Neurobehavioral and psychiatric manifestations can persist into adulthood, although the overall presentation is strongly influenced by the degree of intellectual disability and visual impairment.

From a morphologic lens perspective, other features include (but are not limited to):

  • Midface retrusion

  • Micrognathia

  • Downslanted palpebral fissures

  • Almond-shaped palpebral fissure

  • Prominent nasal bridge

  • Short philtrum

  • Short palm

  • Short metatarsals

  • Single transverse palmar crease

Other characteristic features include early-onset hypotonia, developmental delay and acquired microcephaly, with moderate to profound intellectual disability and prominent speech and language impairment. Progressive high myopia and retinal dystrophy are characteristic ophthalmological manifestations and may lead to significant visual impairment, including impaired night vision and progressive visual-field constriction. Neutropenia is characteristic and may be associated with recurrent infections and recurrent oral ulcers. Growth and weight patterns are distinctive, with poor weight gain and feeding difficulties during infancy and childhood followed by relatively rapid development of truncal obesity during later childhood or adolescence; short stature is also common. Joint laxity may contribute to kyphosis and scoliosis. Other reported features include constipation, dental abnormalities and, less commonly, seizures, cardiac abnormalities and renal abnormalities.

Early diagnosis is important to identify and manage visual impairment, neutropenia and associated infections or oral complications; recognise developmental, neurological, gastrointestinal and musculoskeletal complications; provide appropriate developmental, educational and psychiatric assessment and support; and facilitate genetic counselling and assessment of potentially affected relatives.

Selected references and further reading — Morphologic lens

Jones KL, Jones MC, del Campo M. Smith's recognizable patterns of human malformation. 8th ed. Philadelphia: Elsevier; 2021.

Reardon W. The bedside dysmorphologist: a guide to identifying and assessing congenital malformations. 2nd ed. Oxford: Oxford University Press; 2016.

Allanson JE, Biesecker LG, Carey JC, Hennekam RCM. Elements of morphology: introduction. Am J Med Genet A. 2009;149A(1):2-5. doi:10.1002/ajmg.a.32601.

Hennekam RCM, Biesecker LG, Allanson JE, Hall JG, Opitz JM, Temple IK, Carey JC; Elements of Morphology Consortium. Elements of morphology: general terms for congenital anomalies. Am J Med Genet A. 2013;161A(11):2726-2733. doi:10.1002/ajmg.a.36249.