Costello syndrome Dr Trisha Macnair There are an estimated 300 cases of this rare inherited disorder, but more may have gone unrecognised. We look at the symptoms and possible causes.

In this article

What is it? Symptoms

Who's affected? What causes it?

What's the treatment? Advice and support

Costello syndrome is a rare inherited disorder, also known as faciocutaneoskeletal syndrome or FCS syndrome. It was first reported in 1977 by a paediatrician in New Zealand, who described two children with similar physical features and mild learning disabilities. There's also a characteristic pattern of growth, behavioural problems and physical appearance.

Children with Costello syndrome are born with a normal or slightly high birth weight. In a few cases, mothers report decreased foetal movement during the pregnancy and in one in three cases, there's excessive fluid around the baby in the womb (polyhydramnios).

Typical features, which become more obvious as the child grows, include:

• Short stature
• Delayed bone age
• Loose, lax, stretchy skin - around the neck, palms, soles and fingers
• Curly hair
• Papillomata (small fleshy growths) around the mouth and nose
• A characteristic facial appearance (wide nostrils, depressed nasal bridge, low-set ears with large earlobes)
• Broad mouth and thick lips
• Pigmented skin
• Drooping of the upper eyelid (ptosis)
• Squint (strabismus)

Heart problems such as hypertrophic cardiomyopathy or abnormal heart rhythms are common, as is reflux or flowing back of the contents of the stomach into the gullet, which may cause feeding problems. There may be an increased risk of various cancers.

Affected children may have learning difficulties, but many have warm social personalities.

There are an estimated 300 cases of Costello syndrome worldwide, although more may have gone undiagnosed.

It is now known that mutations in the HRAS gene causes Costello syndrome. This gene is involved in the manufacture of a protein that helps control cell growth and division. In Costello syndrome mutations of this gene cause cells to grow and divide constantly rather than in response to specific signals to do so. This constant abnormal cell division and overgrowth results in cancerous and non-cancerous tumour growth and is thought to be responsible for the other characteristic signs of Costello syndrome.

Costello syndrome is believed to have an autosomal dominant pattern of inheritance. Almost all cases have arisen without a family history of the condition as a result of new mutations. There is now a genetic test available to test for Costello syndrome.

There's no cure for Costello syndrome but treatments are in development. However, supportive care - from help with feeding in early childhood to special education - and treatment for complications such as heart problems can help affected children reach their potential.

International Costello Syndrome Support Group

Website: www.costellokids.org.uk

Contact a Family

Helpline: 0808 808 3555
Website: www.cafamily.org.uk

This article was last medically reviewed by Dr Rob Hicks in January 2008