Freeman-Sheldon syndrome (FSS) is a very rare genetic disorder characterized by a small, puckered mouth, which gives the appearance of a person whistling. For this reason, Freeman-Sheldon syndrome is also known as whistling face syndrome. FSS may also be referred to as windmill vane hand syndrome or craniocarpotarsal dystrophy.
Ernest Freeman and Joseph Sheldon, two British physicians, first described this distinct disorder in 1938. The syndrome is characterized by skeletal malformations in the hands and feet and facial abnormalities.
In addition to the small mouth, characteristics of FSS include a flat, mask-like face, underdeveloped nose cartilage, contracted muscles of the joints of fingers and hand, and clubbed feet. Most of the features of FSS are caused by muscle weakness. In addition to those characteristics noted above, individuals with FSS may also have crossed eyes, drooping upper eyelids, scoliosis, hearing loss, and walking difficulties. Intelligence is usually normal, health is generally good, and life expectancy is normal.
Usually, FSS follows an autosomal dominant inheritance pattern. With this pattern of inheritance, the syndrome appears when a child inherits one defective gene from one parent. In some families, FSS follows an autosomal recessive inheritance pattern. In these cases, the condition only appears when a child receives the same defective gene from each parent. This syndrome can also occur sporadically, that is, neither parent passes on the gene responsible for FSS.
As of 2001, the gene responsible for FSS has not been located. Current genetic research is focusing on chromosome 11. Some experts consider FSS a form of distal arthrogryposis, which has been mapped to chromosome 11, specifically to location 11p15.5.
Freeman-Sheldon syndrome is extremely rare. It affects males and females in equal numbers.
Signs and symptoms
Doctors can recognize Freeman-Sheldon syndrome at birth. Babies born with FSS usually have distinct abnormalities of the head, face, hands, and feet.
Facial abnormalities usually include an extremely small and puckered mouth, a full forehead, prominent cheeks, and thin, pursed lips. The middle part of the face may be flat, giving the baby a mask-like appearance. There may be a high palate, unusually small jaw, abnormally small tongue, and a raised mark or dimpling in the shape of an "H" or "V" on the chin. Other common facial abnormalities associated with FSS include widelyspaced, deep-set eyes, crossed eyes, and down-slanting eye openings.
Infants born with FSS may have malformations of the hands or feet, including clubbed feet. The muscles in the joints of the fingers and hands may be contracted.
Characteristics of FSS are often linked with other problems such as impaired speech, swallowing and eating difficulties, and vomiting. Children may fail to grow and gain weight at the expected rate, and there may be respiratory problems. Although most of the characteristics of FSS will be discovered fairly early in life, scoliosis (curvature of the spine) may be diagnosed later in childhood or adolescence as the child grows.
As of 2001, there is no laboratory test to diagnose Freeman-Sheldon syndrome. Because many of the characteristics of FSS are present at birth, doctors can recognize and diagnose FSS following birth based on these characteristics. FSS has also been diagonsed prenatally using ultrasound imaging. Since the gene responsible for FSS has not yet been identified, chromosomal tests are not used in diagnosis.
Because FSS can run in families, parents of children with FSS may wish to seek genetic counseling.
Treatment and management
Most children with Freeman-Sheldon syndrome will require orthopedic or plastic surgery to correct their hand problems, clubbed feet, and tight mouth. Plastic surgery can improve the function and appearance of the mouth and nose. Craniofacial surgery can reshape the frontal bone and increase eyelid openings. A potential surgical complication in FSS patients is malignant hyperthermia (a serious problem with inhaled anesthetic agents). A muscle biopsy prior to surgery can rule out this risk. The thumb may be repositioned to improve hand function.
Life expectancy for infants diagnosed with Freeman-Sheldon syndrome is normal. Infants and children with FSS may be referred to physical and speech therapists. Physical therapy may help children improve the use of their hands, and it also can improve ambulation (walking). Speech therapy may improve tongue movement, which helps speech and swallowing. Sometimes, adaptive devices are recommended to aid muscular function.
Bamshad, M., L.B. Jorde, and J.C. Carey. "A Revised and Extended Classification of Distal Arthrogryposis." American Journal of Medical Genetics 65 (1996): 277-281.
Lev, D., et al. "Progressive Neurological Deterioration in a Child with Distal Arthogryposis and Whistling Face." Journal of Medical Genetics 37 (2000): 231-233.
Ohyama, K., et al. "Freeman-Sheldon Syndrome: Case Management from Age 6 to 16 Years." Cleft Palate Craniofacial Journal 34 (1997): 151-153.
Freeman-Sheldon Parent Support Group. 509 East Northmont Way, Salt Lake City, UT 84103-3324. (801) 364-7060.
Lisa Ann Fratt