Rubinstein–Taybi syndrome (RTS) is a rare genetic condition characterized by short stature, moderate to severe learning difficulties, distinctive facial features, and broad thumbs and first toes.

[citation needed] Typical features of the disorder include: A 2009 study found that children with RTS were more likely to be overweight and to have a short attention span, motor stereotypies, and poor coordination.

This condition affects men and women equally, and is often misdiagnosed with other diseases or disabilities that result in delayed mental development.

If one copy of the CREBBP gene is deleted or mutated, cells make only half of the normal amount of CREB binding protein.

A reduction in the amount of this protein disrupts normal development before and after birth, leading to the signs and symptoms of Rubinstein–Taybi syndrome.

Although researchers do not know how a reduction in the amount of p300 protein leads to the specific features of Rubinstein–Taybi syndrome, it is clear that the loss of one copy of the EP300 gene disrupts normal development.

[21] Rubinstein–Taybi syndrome was first unofficially mentioned in a French orthopedic medical journal in 1957 by Greek physicians' doctors: Michail, Matsoukas, and Theodorou.

The medical journal reported a case concerning a seven-year-old boy with radically deviated/arched thumbs, long nose, muscular hypotonia, along with physical and mental underdevelopment.

[citation needed] Dr. Jack Herbert Rubinstein, an American pediatrician reported assessing a three-year-old girl with unusual facial and digital findings in 1958.

Rubinstein graduated from Harvard Medical School and worked as the director of the Hamilton County Diagnostic Clinic for the Mentally Retarded.

[citation needed] In 1961, Dr. Hooshang Taybi, an Iranian-American pediatric radiologist, reported having assessed a three-year-old boy that appeared to have the same syndrome as described by Rubinstein.