Schwartz Jampel syndrome was first described in 1962. It is an autosomal recessive disease with generalized myotonic myopathy and skeletal dysplasia. A mutation in the HSPG2 gene occurs. Approximately 150 cases have been reported in literature. A 4-year-old girl presented to the pediatric neurology clinic due to difficulty in walking. The patient had difficulty opening her mouth and swallowing. She was unable to eat solid foods and was bottle fed. She was able to stand leaning forward, with her legs open and with one hand supported. Bilateral blepharospasm, posterior cleft palate, microstomia, pursed lips, kyphoscoliosis, contracture in the elbows, long thin fingers and campodactyly in the bilateral 5th fingers were present. Myotonic contraction with thenar percussion was observed. Previously undescribed mutation was determined in HSPG2 gene in the genetic study. Oral carbamazepine therapy was initiated and 1.5 months later the patient`s muscle rigidity had decreased and her motor skills had improved. This report contributes to the literature by defining a new mutation in HSPG2 gene and showing the importance of early diagnosis of the disease.

Keywords: Schwartz Jampel syndrome, carbamazepine, myotonia