Rett syndrome (RTT) is a genetic disorder that typically becomes apparent after 6–18 months of age and almost exclusively in females. Symptoms include impairments in language and coordination, and repetitive movements. Those affected often have slower growth, difficulty walking, and a smaller head size. Complications of Rett syndrome can include seizures, scoliosis, and sleeping problems. The severity of the condition is variable.
Rett syndrome is due to a genetic mutation in the MECP2 gene, on the X chromosome. It almost always occurs as a new mutation, with less than one percent of cases being inherited. It occurs almost exclusively in girls; boys who have a similar mutation typically die shortly after birth. Diagnosis is based on the symptoms and can be confirmed with genetic testing.
There is no known cure for Rett syndrome. Treatment is directed at improving symptoms. Anticonvulsants may be used to help with seizures. Special education, physiotherapy, and leg braces may also be useful depending on the needs of the child. Many of those with the condition live into middle age.
The condition affects about 1 in 8,500 females. In 1999, Lebanese-American physician Huda Zoghbi discovered the mutation that causes the condition.