A genetic disease characterized by mental deficiency, broad thumbs and toes, short stature , and characteristic facial features.
Causes, incidence, and risk factors
Rubinstein-Taybi syndrome is a rare condition, affecting about 1 in 125,000 people. The proof of this disease being genetic was shown by discovery of mutations in, or loss of, a gene (CREBB) on chromosome 16 that rarely is inherited in an autosomal dominant manner. However, most cases are not inherited, rather they are sporadic and likely due to a new mutation affecting the patient, but not his or her parents. The classic finding is broad thumbs and great toes, but the condition is manifested by many other findings including: short stature , a peculiar face, low-set ears , port-wine-stain, undescended testicles in the male, and downward slant of the eyes.
Signs and tests
decreased IQ in range of 30-80 hypoplastic maxilla (small jaw), narrow palate, crowded teeth an unsteady or stiff walking gait low-set ears or malformed ears ptosis ( drooping eyelid )
cataractcoloboma (a defect in the iris of the eye)
cryptorchidism or other testicular problems macrocephaly (excessively large head) or microcephaly (excessively small head)
skeletal (limb) abnormalities including the last segment of the other fingers/toes appearing broad on x-rays or physical examination genetic testing, including deletion testing to see if the CREBB gene is missing or mutation testing
Treatment
There is no specific treatment for Rubinstein-Taybi syndrome. Symptoms such as mental retardation are treated as necessary with speech and cognitive therapy. Treatment may not be necessary in all cases.
Support groups
Rubinstein-Taybi Parents Group USA 1-888-447-2989
Expectations (prognosis)
The majority of children can learn to read at an elementary level. The majority have delayed motor development, but average age to learn to walk is by 2 1/2 years of age.
Complications
Complications vary depending on the symptoms that are present. Feeding difficulties are common in infancy. Recurrent ear infections with hearing loss can result. Surgical repair of thumbs or great toes can sometimes improve grasp or relieve discomfort. Both abnormal heart structures at birth and abnormal heart rhythms have been reported. There is an increased risk for keloid formation of the skin.
Calling your health care provider
Call for an appointment with your health care provider if you child does not seem to be developing normally. An appointment with a geneticist is appropriate if the provider finds signs of Rubinstein-Taybi syndrome such as broad thumbs and toes.
Prevention
There is no known prevention for this rare disorder. Prenatal genetic testing may be available if the affected parent has a known mutation.