Rubinstein-Taybi syndrome
Rubinstein-Taybi syndrome, also known as Broad thumb-hallux syndrome, is a genetic condition characterized by distinct physical and developmental features. Individuals with this syndrome typically exhibit small stature, intellectual disabilities, and notably large thumbs and toes. Other physical traits may include a long nose, tiny mouth, wide-set eyes with sagging eyelids, misshapen ears, and dental issues. The condition is linked to a mutation in the CREBBP gene located on chromosome 16 and occurs in an estimated 1 to 3 cases per 100,000 people, often with higher rates in institutional settings.
Symptoms manifest lifelong, and affected individuals may experience delays in motor skills and other health complications, such as heart and digestive issues. Treatment often involves a multidisciplinary approach, including physical, occupational, and behavioral therapies, as well as surgical interventions for specific concerns. While the life expectancy of individuals with Rubinstein-Taybi syndrome can be average, it largely depends on the severity of associated health problems. Ongoing research continues to explore the genetic underpinnings of this syndrome, reflecting the evolving understanding of its complexities.
Rubinstein-Taybi syndrome
ALSO KNOWN AS: Broad thumb-hallux syndrome
ANATOMY OR SYSTEM AFFECTED: Bones, ears, eyes, feet, genitals, hands, head, heart, mouth, nose, teeth
DEFINITION: A syndrome typically characterized by small skeletal stature, mental retardation, and large thumbs and toes
CAUSES: Genetic mutation
SYMPTOMS: Mental retardation, poor motor skill development, small body size, small head, large thumbs and big toes, long nose, tiny mouth, wide-set eyes with sagging eyelids; misshapen ears; bunched teeth; undescended testicles; excessive body hair
DURATION: Lifelong
TREATMENTS: Physical, behavioral, and occupational therapies; surgical correction of knees, testicles, eyes, teeth; medications or surgeries for various complications; antibiotics for related infections; institutionalization and constant monitoring
Causes and Symptoms
Medical investigators have linked Rubinstein-Taybi syndrome to a of the CREB-binding protein (CREBBP) gene on chromosome 16. Studies estimate an occurrence rate ranging from 1 to 3 cases per 100,000 people, with a higher incidence in institutions. The syndrome hinders physical and intellectual development. Patients are intellectually disabled, and they do not develop motor skills at normal rates.
Body size, particularly of the head, is much smaller than that attained by typical children because growth is stunted. Most patients have thumbs and/or big toes that are unusually large and have flat tips. Sometimes, the big toes are separated from the smaller toes, which are grouped closely together.
A patient’s face often bears distinctive characteristics, including a long nose, a tiny mouth, and far-apart eyes with sagging eyelids and extended eyelashes. The patient sometimes squints. The ears are frequently misshapen. Inside the mouth, the are bunched together on steep palates. In males, the testes usually do not descend. Both genders often grow more body than do normal children.
Treatment and Therapy
Medical care for Rubinstein-Taybi syndrome includes various physical, behavioral, and occupational therapies to treat specific problems. Speech therapy helps patients learn to communicate. Corrective shoes or surgery may be necessary to aid walking if toe size and placement interfere with movement. The knees and testicles may also require surgical adjustment. Eye surgery may be necessary if eyeglasses do not resolve vision flaws. Dentistry corrects faulty bites.
Patients sometimes suffer seizures, tumors, and heart, lung, or digestive complications and require appropriate medications or surgeries. Antibiotics mitigate urinary tract infections, ear infections, and kidney problems related to this syndrome. Patients are vulnerable to heart or breathing problems while anesthetized. Many require institutionalization and constant monitoring because they experience sleeping and eating difficulties. Individuals with this syndrome can attain average life spans if they do not suffer serious physical problems or infections.
Perspective and Prospects
Greek physicians J. Michail, J. Matsoukas, and S. Theodorou reported a case in 1957 of a child with the traits of this syndrome. Unaware of that publication, in the late 1950s Jack H. Rubinstein and Hooshang Taybi observed distinctive characteristics in seven patients. Taybi delivered their joint paper at the 1962 Society for Pediatric Radiology meeting. The next year, they published a 1963 article outlining this syndrome. In the 2020s, medical researchers continued genetic investigations for this syndrome.
Bibliography
Awan, Neelam, et al. "The Behavioral Phenotype of Rubinstein-Taybi Syndrome: A Scoping Review of the Literature." American Journal of Medical Genetics, 21 June 2022, doi.org/10.1002/ajmg.a.62867. Accessed 8 Apr. 2024.
Rubinstein-Taybi Syndrome. http://www.rubinstein-taybi.org.
Rubinstein, Jack H., and Hooshang Taybi. “Broad Thumbs and Toes and Facial Abnormalities: A Possible Mental Retardation Syndrome.” American Journal of Diseases of Children 105 (1963): 588–608.
“Rubinstein-Taybi Syndrome.” MedlinePlus, August 4, 2011.
“Rubinstein-Taybi Syndrome; Williams Syndrome.” American Journal of Medical Genetics Supplement 6. New York: Wiley-Liss, 1990.
Taybi, Hooshang. Handbook of Syndromes and Metabolic Disorders: Radiologic and Clinical Manifestations. St. Louis, Mo.: Mosby, 1998.
Wiley, Susan, et al. “Rubinstein-Taybi Syndrome Medical Guidelines.” American Journal of Medical Genetics 119A, no. 2 (June 1, 2003): 101–110.