Hecht syndrome: A striking genetic disorder in which abnormally short muscles in the jaw make it impossible to open the mouth fully (trismus) and abnormally short muscles in the hands keep the fingers straight when the hand is flexed back (pseudocamptodactyly). The difficulty in opening the mouth fully can cause severe infant feeding problems. It also complicates dental care and intubation for anesthesia. The hands may be so tightly fisted the infant crawls on his or her knuckles. The pseudocamptodactyly impairs manual dexterity and causes occupational and social disability. Many patients require surgical correction of contractures. The syndrome is considered a type of distal arthrogryposis.
The gene for the syndrome is transmitted as an autosomal dominant trait passing from parent to child, irrespective of sex. There is variable expressivity but high penetrance.
The Hecht syndrome has been served as an historic marker. For example, a large American family with the syndrome was traced to a Dutch girl who migrated to Tennessee soon after the American Revolution. A large Dutch family with many affected members has also been described. The Dutch and American families are now believed to be related.
Hecht syndrome was first described by the pediatrician/geneticist Frederick Hecht and orthopedist Rodney K. Beals of the Oregon Health Sciences University. They called the syndrome "Inability to Open the Mouth Fully." It now also goes by the precise but hard-to-remember name of trismus pseudocamptodactyly syndrome. It has also been called the Hecht-Beals syndrome and the Dutch-Kentucky syndrome.