Rubinstein-Taybi synrome (also known as Broad Thumb-Hallux syndrome) is a condition characterized by short stature, moderate to severe mental retardation, distinctive facial features, and broad thumbs and first toes. Other features of the disorder vary among affected individuals. People with this condition have an increased risk of developing noncancerous and cancerous tumors, leukemia, and lymphoma. This condition is inherited in an autosomal dominant pattern and is uncommon, occurring in an estimated 1 in 125,000 births.