Your browser does not support javascript:   Search for gard hereSearch for news-and-events here.


Genetic and Rare Diseases Information Center (GARD)

Print friendly version

Trismus-pseudocamptodactyly syndrome

Other Names for this Disease
  • Arthrogryposis distal type 7
  • Distal arthrogryposis type 7
  • Dutch-Kentucky syndrome
  • Hecht syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

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?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is trismus-pseudocamptodactyly syndrome?

Trismus-pseudocamptodactyly syndrome 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] Both sporadic occurrence and autosomal dominant inheritance have been reported in the medical literature.[1] The most serious complications of the condition occur as a result of the limited mobility of the mouth.[2] Treatment may involve surgical correction and physical therapy.[1][2] 
Last updated: 4/13/2011

What are the signs and symptoms of trismus-pseudocamptodactyly syndrome?

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

What is the typical life expectancy for people with trismus-pseudocamptodactyly syndrome?

Overall individuals with trismus-pseudocamptodactyly syndrome have normal development[2] and life expectancy does not appear to be reduced.
Last updated: 4/13/2011

How might trismus-pseudocamptodactyly syndrome be treated?

While the best treatment options for trismus-pseudocamptodactyly syndrome have not been well established[1][2] cases of improvement of mouth mobility following surgery and physical therapy have been reported in the medical literature.[1][2] We recommend that you speak with your healthcare provider to learn more about specific treatment options.
Last updated: 4/13/2011

Is trismus-pseudocamptodactyly syndrome genetic?

Both sporadic and genetic cases of trismus-pseudocamptodactyly syndrome have been reported in the medical literature.[1][2] "Sporadic" can refer to either a genetic disorder that occurs for the first time in a family due to a new mutation (gene change), or to the chance occurrence of a non-genetic disorder or abnormality that is not likely to recur in a family. 

The genetic cases reported were inherited in an autosomal dominant fashion. In some families, trismus-pseudocamptodactyly syndrome can be caused by mutations in the MYH 8 gene

GeneTests lists laboratories offering clinical genetic testing and research genetic testing for this condition. Clinical genetic tests are ordered to help diagnose a person or family and to aid in decisions regarding medical care or reproductive issues. Research genetic tests may be used to find disease-causing genes, learn how genes work, or aid in the understanding of a genetic disorder. In many cases research test results are not shared with the patient or physician. Talk to your health care provider or a genetic professional to learn more about clinical and research testing for this condition.

Last updated: 4/13/2011

How can I find other parents with children with trismus-pseudocamptodactyly syndrome?

We are not aware of a disease advocacy organization specifically for trismus-pseudocamptodactyly syndrome and their families. Still, you may find the following support organization to be helpful.

The National Organization for Rare Disorders (NORD) is a federation of more than 130 nonprofit voluntary health organizations serving people with rare disorders. You can order a printed report on trismus-pseudocamptodactyly syndrome through NORD’s Web site, or by calling or writing the NORD offices.

National Organization for Rare Disorders (NORD)
55 Kenosia Avenue
PO Box 1968
Danbury, CT 06813-1968
Toll-free: 1-800-999-6673 (voicemail only)
Telephone: 203-744-0100
TDD: 203-797-9590
Fax: 203-798-2291
Web site:

Last updated: 3/29/2013

  • Carlos R, Contreras E, Cabrera J. Trismus-pseudocamptodactyly syndrome (Hecht-Beals' syndrome): case report and literature review. Oral Dis. 2005 May;
  • Lefaivre JF, Aitchison MJ. Surgical correction of trismus in a child with Hecht syndrome. Ann Plast Surg. 2003 Mar;