Schwartz-Jampel syndrome (SJS) is a rare, inherited condition of the skeletal and muscle systems that causes short stature, joint limitations, and particular facial features.
First described in 1962, SJS is now a clearly defined syndrome that is divided into two types. Type 1A is the classical form that develops in early childhood, usually between the first and third year of life. Type 1B is less common but more severe and its symptoms are present at birth. Both types of SJS involve generalized disease of the muscles called myopathy. The muscles tend to be quite stiff and are unable to relax normally. This is a condition known as myotonia. The myotonia causes many joints in the body to stay in a bent or flexed position (joint contractures).
In addition to muscle problems, the bones in the skeleton do not develop normally and this is why SJS may also be called a type of skeletal dysplasia. Abnormal bone shape and poor bone growth result in decreased total height, incorrect arm and leg postures, as well as curving of the spine (scoliosis).
Unique facial features of SJS include narrow eye openings with drooping eye lids, a small mouth, and puckered lips. These features are also due to the stiffness of the muscles that support the face and individuals with SJS appear to have a fixed facial expression.
Persons affected with SJS often have normal intelligence, although varying degrees of mental retardation may affect as many as 25% of patients. However, the myotonia may lead to poor speech articulation and drooling so that affected individuals are sometimes misdiagnosed as having mental retardation.
Respiratory and feeding difficulties are frequent with SJS Type 1B due to the more severe nature of the muscle and bone disease. These problems may be fatal in early infancy. Persons with SJS Type 1A have a much longer life expectancy, although this depends on how their disease progresses.
SJS has also been referred to as:
myotonic myopathy, dwarfism, chrondrodystrophy, and ocular and facial abnormalities
spondylo-epimetaphyseal dysplasia with myotonia
Jennifer Elizabeth Neil MS, CGC, The Gale Group Inc., Gale, Detroit,