Last Reviewed June 9, 2009
Symptoms & Characteristics
Cohen syndrome is an
genetic condition that affects various parts of the body and is characterized by developmental delay, mental retardation, small head size (microcephaly), and weak muscle tone (hypotonia). Additional features include progressive nearsightedness (myopia), degeneration of the light-sensitive tissue at the back of the eye (retinal dystrophy), an unusually large range of joint movement (hypermobility), and distinctive facial features. Characteristic facial features include thick hair and eyebrows, long eyelashes, unusually-shaped eyes (down-slanting and wave-shaped), a bulbous nasal tip, a smooth or shortened area between the nose and the upper lip (philtrum), and prominent upper central teeth. The combination of the last two facial features results in an open-mouth appearance.
The features of Cohen syndrome vary widely among affected people. Additional signs and symptoms may include low levels of white blood cells (neutropenia), overly friendly behavior, and obesity that develops in late childhood or adolescence. When obesity is present, it typically develops around the abdomen, with the arms and legs remaining slender. Affected people may also have narrow hands and feet as well as slender fingers.
Treatment
The management and treatment of Cohen syndrome depends on the specific symptoms. Early diagnosis, routine surveillance and treatment may help to manage some of the symptoms and sometimes prevent related problems.
How Common Is It?
Less than 1,000 people have been diagnosed with Cohen syndrome; however, researchers believe additional cases are likely undiagnosed.
Genetics & Inheritance
Cohen syndrome is caused by mutations in the VPS13B gene (commonly called the COH1 gene) cause
Cohen syndrome is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Genetic Testing
Clinical genetic testing for Cohen syndrome may be available
through an in person genetic consultation for people who are considered at risk.
Use our find a genetic professional directory to locate a trained genetic professional
in your area.
Support & More Information
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Alternative Names
- Hypotonia, obesity, and prominent incisors
- Norio syndrome
- obesity-hypotonia syndrome
- Pepper syndrome
- prominent incisors-obesity-hypotonia syndrome