This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Freeman-Sheldon syndrome (FSS) affects the development of the bones, joints, head, and face. Symptoms of FSS are present from birth, and include abnormally flexed joints (joint contractures), spine abnormalities, and a characteristic facial appearance. People with FSS have a small mouth (microstomia) with pursed lips, giving the appearance of a “whistling face”. In addition, they may have deep nasolabial folds (the skin between the nose and the lips) and a V-shaped chin dimple. There may be abnormalities of the eyes such as wide-spaced eyes (hypertelorism) and a narrowing of the eye opening (blepharophimosis). People with FSS often have breathing, eating, and speech problems. The joint and spine problems may get worse over time. FSS is thought to be caused by variants in the MYH3 gene. Most cases occur by chance. Rarely, FSS is inherited in an autosomal dominant manner. Diagnosis is based on a specific set of symptoms, clinical exam, and may be confirmed by the results of genetic testing. Treatment is focused on managing the symptoms and may involve corrective surgery.
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