Schwartz–Jampel Syndrome (SJS) is a rare autosomal recessive disorder characterized by a combination of musculoskeletal abnormalities and continuous muscle contractions.
Clinical Features:
-
Musculoskeletal Features:
- Chondrodysplasia: Abnormal cartilage development leads to short stature and joint contractures.
- Facial Features:
- Blepharophimosis: Narrowing of the eye openings.
- Pursing of the mouth and puckering of the chin due to persistent muscle contraction.
- Stiffness: Muscle stiffness affecting the limbs, often worsened with cold or exertion.
-
Muscle Abnormalities:
- Continuous muscle contraction, even at rest, contributes to stiffness and abnormal posture.
- Despite the muscle contraction, serum creatine kinase (CK) levels are normal or mildly elevated.
-
Electromyography (EMG):
- Abnormal, continuous muscle fiber activity is seen, even in the absence of voluntary movement.
-
Histological Findings:
- Muscle biopsy typically appears normal or shows nonspecific changes.