Trismus-pseudocamptodactyly syndrome

Trismus-pseudocamptodactyly syndrome (TPS), also known as Hecht syndrome or Dutch-Kentucky syndrome, is a rare congenital disorder characterized by the inability to fully open the mouth (trismus) combined with a distinctive hand abnormality in which the fingers appear to be permanently bent (camptodactyly) when the wrist is dorsiflexed (bent backward), but can extend normally when the wrist is in a neutral or flexed position — hence the term 'pseudocamptodactyly.' The condition primarily affects the musculoskeletal system, specifically the muscles and tendons of the jaw and hands. The limited mouth opening is caused by shortening of muscles or fibrous bands related to the pterygoid and other masticatory muscles, which can lead to difficulties with eating, dental care, and intubation during anesthesia — a particularly important clinical concern. The hand findings result from shortened flexor tendons of the fingers. Additional features may include short stature, foot deformities (such as talipes equinovarus or clubfoot), and occasionally hip abnormalities. The syndrome has been linked to mutations in the MYH8 gene, which encodes perinatal myosin heavy chain, a protein important in muscle development. There is no cure for trismus-pseudocamptodactyly syndrome. Management is supportive and symptom-directed. Surgical interventions such as coronoidectomy or release of fibrous bands may be considered to improve mouth opening. Physical therapy and stretching exercises can help maintain hand and jaw function. Careful planning for anesthesia is essential due to the restricted oral opening, and fiberoptic or nasal intubation techniques may be required. Genetic counseling is recommended for affected families.

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