As young babies, feeding difficulties are common in Cohen syndrome and some infants may need nasogastric tube feeding (where food is passed into the stomach via a tube in the nose). Some babies have stridor (noisy breathing), due to a floppy windpipe.
Young children with Cohen syndrome have developmental delay. They learn to walk later than the average child and their speech takes longer to develop. All children have special educational needs, with the majority attending schools for children with moderate-to-severe learning difficulties. Children with Cohen syndrome are typically very sociable and affectionate, however, a few can have behavioural difficulties that fall within the autistic spectrum (see entry Autistic Spectrum disorders, including Asperger syndrome).
From around ten years, children with Cohen syndrome put on more weight, especially around their tummies. However, they do not usually become generally obese. Many are short for their age and have microcephaly. Individuals with Cohen syndrome have loose, flexible joints and hypotonia (low muscle tone), which can result in difficulties with balance and coordination.
Children with Cohen syndrome often have a high roof to their mouth with overcrowding of their teeth. A specific feature of Cohen syndrome is a low number of white blood cells, called neutrophils, used by the body to fend off bacterial infections. Dental and skin infections may occur a little more frequently in some people with Cohen syndrome, however, it is rare to suffer from severe infections. Autoimmune disorders, in particular diabetes (see entry Diabetes Mellitus), thyroid disorders and coeliac disease, have been reported in some individuals.
Visual problems affect nearly all children with Cohen syndrome. These start during the preschool years with myopia (short-sightedness), which becomes more severe throughout childhood. In addition, the area at the back of the eye, known as the retina, gradually reduces in function causing poor vision in dim light and loss of the outer ranges of the visual field (known as a retinal dystrophy). Older children and adults with Cohen syndrome find it particularly difficult to see in reduced light or at night time and have 'tunnel vision'. Their visual acuity (close vision), however, usually remains quite good. By adult life, many people with Cohen syndrome are registered partially-sighted or blind.
Adults with Cohen syndrome usually continue to live at home or in residential care as their level of independence is limited. They are usually friendly people who enjoy socialising and group activities. They remain healthy and do not have a shortened lifespan.