Cohen syndrome

Cohen syndrome (also known as Pepper syndrome or Cervenka syndrome) is a very rare autosomal recessive genetic disorder with varied expression, characterised by obesity, intellectual disability, distinct craniofacial abnormalities and potential ocular dysfunction.

Genetics

This syndrome is believed to be a gene mutation in chromosome 8 at locus 8q22 gene COH1. It has an autosomal recessive transmission with variable expression. There is evidence that this syndrome has a different mutation in the same gene as Mirhosseini–Holmes–Walton syndrome.

Diagnosis

Cohen syndrome is diagnosed by clinical examination but is often difficult due to variation in expression. Ocular complications, though rare, are listed as optic atrophy, microphthalmia, pigmentary chorioretinitis, hemeralopia (decreased vision in bright light), myopia, strabismus, nystagmus and iris/retinal coloboma.

General appearance is obesity with thin/elongated arms and legs. Micrognathia, short philtrum and high vaulted palate are common. Variable intellectual disability with occasional seizure and deafness also is characteristic of Cohen syndrome.

Management

Some of the symptoms of Cohen syndrome can be addressed through early intervention with medical specialists. Those who have this disease may benefit from early exposure to speech, physical, and occupational therapy to correct symptoms such as joint overflexibility, developmental delays, hypotonia, and motor clumsiness. Diagnosis may potentially be delayed due to the lack of a definitive molecular test as well as the clinical variability of published case reports.

Glasses are beneficial to those who have severe nearsightedness, whereas individuals with retinal degeneration need training for the visually impaired, which is usually more beneficial when this is addressed at a young age. Younger patients start out having unimpaired vision, but it starts to deteriorate at a young age and does so slowly. If vision is able to improve with the use of glasses, it usually improves cognitive skills as well.

The type of therapy needed for each individual varies, as not every affected individual would benefit from speech, physical, and occupational therapies. The type of therapy for each person is highly individualized. Individuals who have Cohen syndrome may also benefit from psychosocial support.

Many people who have Cohen syndrome also suffer from neutropenia which is a condition in which an individual has an abnormally low number of white blood cells called neutrophils. Having this condition may make these individuals susceptible to infections. Granulocyte-colony stimulating factor (G-CSF) is one possible treatment for neutropenia.

Monitoring weight gain and growth is crucial, as well as annual ophthalmologic and hematologic evaluations and checkups. While there are treatments available to people with Cohen syndrome, there are no known cures for the disease.

Prevalence

Over the past several years, there have been approximately 50 new cases worldwide. There are population groups with this condition in Australia, New Zealand, the UK and the US. It still seems to go undiagnosed, leaving the number of known cases less than 500.

Etymology

The syndrome is named after Michael Cohen, William Pepper and Jaroslav Cervenka, who researched the illness.

External links

Classification	OMIM: 216550 DiseasesDB: 29622 SNOMED CT: 56604005
External resources	GeneReviews: Cohen Syndrome Orphanet: 193

• GeneReview/NIH/UW entry on Cohen syndrome