Congenital clasped thumb disorder is a condition present at birth (congenital) where a child is born with one or both thumbs folded across the palm of the hand. This condition is caused by muscles and tendons forming incorrectly during fetal development (tendons in the hand may have formed too short or not at all). Studies suggest this condition may have a genetic cause and that males are more at risk for the disorder than females.
Since babies naturally fold their thumb across the palm for the first few months of life, it may be difficult to notice a problem is present. A diagnosis cannot be made until the symptoms remain for at least three to four months after birth. There are three classifications of congenital clasped thumbs: type I the “supple clasped thumb” when the thumb has limited movement; type II the “clasped thumb with hand contractures” when the thumb may not bend towards the back of the hand or extend away from the body due to hardened tendons and muscles; and type III the “arthrogryposis clasped thumb” when the thumb displays severely limited motion.
Treatments for congenital clasped thumb disorder are based upon the level of movement of the thumbs. In type I cases and mild type II cases, affected individuals may be given a splint to gradually set the thumb into its correct place. Splints may be in place for three to six months, although they can be continued for longer. Treatment with a splint is most effective if used in infants six months or younger. In more serious type II and type III cases, in which the person affected by the disorder is older than six months, surgery may be considered.
If your child has been diagnosed with congenital clasped thumb disorder, talk to your doctor about the most current treatment options. In addition, a genetic counselor can help discuss inheritance and risks to other family members. Support groups are available for more resources and information.