Sclerosteosis

Sclerosteosis is a rare genetic disorder characterized by abnormal bone growth. It is caused by mutations in the SOST gene, which is involved in the regulation of bone formation. The condition is primarily found in the Afrikaner population of South Africa, where it has a prevalence of about 1 in 100,000.

Symptoms and Signs

The symptoms of sclerosteosis typically become apparent in early childhood. They include:

• Facial distortion due to overgrowth of the skull and jaw bones
• Hearing loss caused by the overgrowth of bones in the ear
• Increased bone density (sclerosis), particularly in the skull and long bones
• Tall stature due to overgrowth of the long bones
• Hand abnormalities such as large hands and fingers
• Foot abnormalities such as large feet and toes

Causes

Sclerosteosis is caused by mutations in the SOST gene, which is located on chromosome 17. This gene provides instructions for making a protein that regulates bone formation. Mutations in the SOST gene lead to an overproduction of bone, resulting in the symptoms of sclerosteosis.

Diagnosis

The diagnosis of sclerosteosis is typically based on the characteristic physical features and confirmed by genetic testing. Imaging studies such as X-rays and CT scans can also be used to assess the extent of bone overgrowth.

Treatment

There is currently no cure for sclerosteosis. Treatment is aimed at managing the symptoms and may include surgery to relieve pressure on the brain and nerves caused by bone overgrowth.

See also

• Van Buchem disease, a related condition caused by a different mutation in the SOST gene
• Osteopetrosis, a group of conditions characterized by increased bone density