Acknowledgement of Freeman-Sheldon syndrome has not been added yet.

The exact prevalence of this disorder is unknown. There are less than 100 cases reported since the syndrome was first described by Dr. Freeman and Dr. Sheldon in 1938. It is under-diagnosed because it shares physical features as other syndromes.

Name	Abbreviation
Freeman-Sheldon Syndrome	FSS
Craniocarpotarsal dystrophy or dysplasia	FSS
Whistling face syndrome	FSS
Whistling face-windmill vane hand syndrome	FSS
distal arthrogryposis type 2A	DA2A

Freeman-Sheldon syndrome is caused by mutations in the MYH3 gene. This gene is responsible for making a protein in skeletal muscle fibers. It plays an important role in muscle contraction. With the mutated gene, muscles cannot develop normally, even before birth.  

The mutation is an inherited disorder.  Most affected individuals inherit the disease through an autosomal dominant pattern, only one copy of the altered gene from one parent is required.  Some affected individuals can also inherit this disorder through an autosomal recessive pattern. In such cases, two copies of a defective gene from both parents are required to cause the disorder.  The parents each carry one copy of the mutated gene and do not show symptoms of the disorder. The cause or the inheritance pattern can also be unknown, when affected individuals do not have mutations on the MYH3 gene.

This disorder is characterized by the restricted movement of multiple areas of the body at birth. There is abnormal formation of the head, face, hands, and feet. Freeman-Sheldon syndrome affects the joints, particularly the hands or feet. Individuals may develop contractures, or permanent shortening of muscle or connective tissue that cause joints to become less flexible and more rigid. Contractures can limit the range of motion at the joint.  

There are several distinct facial features, such as: an unusually small jaw, prominent forehead, short nose, short philtrum (the groove between the nose and lips), deep folds of the skin (nasolabial folds) between the nose and lips, and a chin dimple in the shape of an “H” or a “V”.  The affected individual can appear to be “whistling”: a small puckered mouth (microstomia) with thin, pursed lips. They may have widely spaced or crossed eyes. The opening of the eyes may be narrow and the upper eyelids may droop.

Children who are affected by this disorder can have speech impairments because of the small mouth.  It is difficult to grow and gain weight because of swallowing and eating difficulties. They can also have life-threatening respiratory problems.

Children with Freeman-Sheldon syndrome are at risk for malignant hyperthermia, a condition in which there is a rapid rise in body temperature and severe muscle contractions in response to certain drugs, especially those used for general anesthesia. Malignant hyperthermia is a serious, life-threatening condition.

In affected individuals, most of the physical abnormalities associated with this disorder can be recognized at birth.  However, some physical abnormalities (such as in the hands or the feet) may not be present at all.

The diagnosis of the Freeman Sheldon syndrome can be confirmed through clinical evaluation, identification of physical abnormalities, detailed patient history, and specialized testing involving advanced imaging techniques.  Computed tomography (CT) scanning is used to determine the presence and severity of specific facial and dental symptoms. A fetal ultrasound can reveal certain physical characteristics before birth.

The treatments regarding Freeman Sheldon syndrome are specific to the symptoms present.  Treatment of this disorder require the efforts of surgeons, dental specialists, speech pathologists, diagnostic physicians, and other medical professionals.  Supportive therapies are available specific to the affected individual. For example, the abnormal development of the mouth can be treated by surgery or by widening it using a special device for a few hours everyday.

There is very minimal data to finalize a prognosis.  It is rare for individuals to die during infancy from respiratory failure.  The life expectancy for affected individuals is the average age.

Individuals affected by Freeman-Sheldon syndrome are encouraged to seek therapies that would help their symptoms.  If there are difficulties faced while performing everyday tasks, they should seek a doctor immediately. If required, surgery may be necessary.

GHR: https://ghr.nlm.nih.gov/condition/freeman-sheldon-syndrome

ORDR: https://rarediseases.info.nih.gov/gard/6466/freeman-sheldon-syndrome/resources/1

OMIM: http://www.omim.org/entry/193700

NORD: http://rarediseases.org/rare-diseases/freeman-sheldon-syndrome/

Orphanet: http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Expert=2053