Freeman–Sheldon syndrome

The Freeman - Sheldon syndrome (FSS, synonyms Craniocarpotarsale dysplasia / dystrophy, whistling -face syndrome ) is an extremely rare, mostly autosomal dominant syndrome but also at any time as a spontaneous mutation can occur in a family for the first time. It is caused by mutations in embryonic myosin heavy chain ( MYH3 ) gene. These mutations lead to damage to the muscles of the embryo, as the muscle contractions generating myosin heads can not work properly.

But the failure of the muscles produces the deformities and loss of motion of the affected joints, drooping eyelids (ptosis ), the characteristic small, " whistling " word and the " depressed face". The expression of the different symptoms and the number of affected joints is very variable, so that a person with FSS may be heavy or light physical disability or even not at all hindered.

Since the mutation only affects the muscles, cognitive development, and intelligence by the syndrome are not affected, in contrast to many phenotypically similar syndromes.