National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Trismus-pseudocamptodactyly syndrome


Other Names:
Hecht syndrome; Dutch-Kentucky syndrome; Distal arthrogryposis type 7; Hecht syndrome; Dutch-Kentucky syndrome; Distal arthrogryposis type 7; Arthrogryposis distal type 7 See More
Categories:
This disease is grouped under:
Distal arthrogryposis; Myosinopathies
Trismus-pseudocamptodactyly syndrome (TPS) is a disorder of muscle development and function.[1] It is characterized by short muscles and tendons resulting in limited range of motion of the hands, legs, and mouth.[1] The most serious complications of the condition occur as a result of the limited mobility of the mouth (trismus).[2] TPS is typically reported to be inherited in an autosomal dominant manner and is caused by mutations in the MYH8 gene.[1][3] Treatment may involve surgical correction and physical therapy.[1][2] 
Last updated: 7/21/2016
While the symptoms of trismus-pseudocamptodactyly syndrome vary from patient to patient, characteristic symptoms include the inability to open the mouth wide (e.g., less than 6 mm, just under 1/4th of an inch) and shortened muscles, including of the hamstrings and calf muscles. As a result of shortened muscles some infants with trismus-pseudocamptodactyly syndrome have closed or clinched fists, club foot, metatarsus adductus, and calcaneovalgus (where the foot bends sharply at the ankle) at birth.[1][2] Children with this syndrome may crawl on their knuckles.[2] In adulthood the syndrome may cause reduced hand dexterity,[1] however hand limitation does not often interfere with normal function.[2] The most serious complications of the condition occur as a result of the limited mobility of the mouth, including impairment of adequate calorie intake, speech development, dental care, and difficulty with intubation.[2]
Last updated: 4/13/2011

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormality of the musculature
Muscular abnormality
0003011
Limitation of joint mobility
Decreased joint mobility
Decreased mobility of joints
Limited joint mobility
Limited joint motion
[ more ] 		0001376
Short stature
Decreased body height
Small stature
[ more ] 		0004322
Symphalangism affecting the phalanges of the hand
Fused finger bones of the hand
0009773
5%-29% of people have these symptoms
Deep philtrum 0002002
Hip dislocation
Dislocated hips
Dislocation of hip
[ more ] 		0002827
Macrocephaly
Increased size of skull
Large head
Large head circumference
[ more ] 		0000256
Mandibular prognathia
Big lower jaw
Increased projection of lower jaw
Increased size of lower jaw
Large lower jaw
Prominent chin
Prominent lower jaw
[ more ] 		0000303
Ptosis
Drooping upper eyelid
0000508
Tall chin
Increased height of chin
Long chin
[ more ] 		0400000
Percent of people who have these symptoms is not available through HPO
Arthrogryposis multiplex congenita 0002804
Autosomal dominant inheritance 0000006
Cutaneous syndactyly of toes
Webbed skin of toes
0010621
Distal arthrogryposis 0005684
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty
[ more ] 		0002015
Facial asymmetry
Asymmetry of face
Crooked face
Unsymmetrical face
[ more ] 		0000324
Feeding difficulties
Feeding problems
Poor feeding
[ more ] 		0011968
Hammertoe
Hammer toe
Hammertoes
[ more ] 		0001765
Metatarsus adductus
Front half of foot turns inward
0001840
Micrognathia
Little lower jaw
Small jaw
Small lower jaw
[ more ] 		0000347
Talipes equinovarus
Club feet
Club foot
Clubfeet
Clubfoot
[ more ] 		0001762
Trismus
Lockjaw
0000211
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Last updated: 7/1/2020
There is no one treatment for trismus-pseudocamptodactyly (TPS), however, there are various strategies that can be used to manage symptoms. Physical and/or occupational therapy may be helpful for individuals experiencing difficulties with walking and hand movement. Surgery may be performed to correct certain musculoskeletal symptoms.[4] There have been reported cases of improvement of mouth mobility following surgery and physical therapy.[1][2][5][6]
Last updated: 7/21/2016
Overall individuals with trismus-pseudocamptodactyly syndrome have normal development[2] and life expectancy does not appear to be reduced.
Last updated: 7/21/2016

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The U.S. National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies. There is a study titled Pediatric Patients With Metabolic or Other Genetic Disorders which may be of interest to you.
  • Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition. 

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Trismus-pseudocamptodactyly syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • My child has trismus-pseudocamptodactyly syndrome. We are very concerned about his trismus. We are interested in receiving any information regarding effective treatment for trismus.  See answer

  • My daughter has trismus-pseudocamptodactyly syndrome. I would like to know what the life expectancy is for people with this syndrome. Are there any support groups? How can I find other families with kids with this syndrome? See answer


  1. Carlos R, Contreras E, Cabrera J. Trismus-pseudocamptodactyly syndrome (Hecht-Beals' syndrome): case report and literature review. Oral Dis. 2005 May; http://www.ncbi.nlm.nih.gov/pubmed/15888111.
  2. Lefaivre JF, Aitchison MJ. Surgical correction of trismus in a child with Hecht syndrome. Ann Plast Surg. 2003 Mar; http://www.ncbi.nlm.nih.gov/pubmed/12800911.
  3. Victor A. McKusick. ARTHROGRYPOSIS, DISTAL, TYPE 7; DA7. In: Marla J. F. O'Neill. OMIM. 2/26/2013; http://www.omim.org/entry/158300.
  4. Trismus Pseudocamptodactyly Syndrome. NORD. 2003; http://rarediseases.org/rare-diseases/trismus-pseudocamptodactyly-syndrome/. Accessed 7/21/2016.
  5. Gasparini G, Boniello R, Moro A, Zampino G, Pelo S. Trismus-pseudocamptodactyly syndrome: case report ten years after. Eur J Paediatr Dent. 2008 Dec; http://www.ncbi.nlm.nih.gov/pubmed/19072009.
  6. Balkin, Daniel M. MD, PhD; Chen, Isaac DDS; Oberoi, Snehlata DDS, MS; Pomerantz, Jason H. MD. Bilateral Coronoidectomy by Craniofacial Approach for Hecht Syndrome-Related Trismus. Journal of Craniofacial Surgery. September 2015; 26(6):1954-1956. http://www.ncbi.nlm.nih.gov/pubmed/26335328.