Schwartz-Jampel Syndrome

At a glance

A very rare autosomal recessive condition manifested by a combination of muscle stiffness (hypertrophied muscle) and mild, largely nonprogressive muscle weakness (myotonia). Facial dysmorphism, blepharospasm and a puckered chin, short stature and skeletal dysplasia.

Synonyms

Catel-Schwartz-Jampel Syndrome; Schwartz-Jampel-Aberfeld Syndrome; Chondrodystrophia Myotonia.

Genetic inheritance

Autosomal recessive.

Incidence

Fewer than 100 cases reported.

Pathophysiology

Three types are recognized. Type Ia is usually recognized in childhood and is associated with moderate bone dysplasia. Type IB is recognized at birth and is associated with more pronounced bone dysplasia. Type II is recognized at birth and is associated with increased mortality. The SJS-I locus (1p34-p36) maps to a region that contains the gene encoding perlecan (HSPG2). This heparan sulphate proteoglycan is highly expressed in cartilage and basement membranes. Three mutations in this gene have been described in families with this syndrome. Contractures are most severe by mid-adolescence.

Diagnosis

Problems with the motor development become evident during the first year of life. The characteristic dysmorphic features lead to an early diagnosis.

Clinical aspects

Features include facial malformations (microstomia, micrognathia, retrognathia, blepharophimosis, short palpebral fissures, telecanthus, sad “fixed” facies, low-set ears, short neck), and musculoskeletal signs (myopathy, myotonia, muscular hypertrophy, restricted joint mobility, osteoporosis, dislocated hip, delayed bone age, epiphyseal anomaly, kyphosis, scoliosis, pectus carinatum, abnormal vertebral size/shape, anterior bowing of the long bones). Mental retardation (20%) and areflexia/hyporeflexia are described. Short stature, intrauterine growth retardation, myopia, cataract, umbilical hernia, generalized hirsutism, feeding and swallowing difficulties, and recurrent hyperthermia may be observed. Severe rhabdomyolysis without anesthesia has been reported.

Precautions before anesthesia

An anesthesiology consultation is highly recommended before elective surgery. Detailed examination of the airway is essential. Evaluate the extent of the myopathy.

Anesthetic considerations

The airway features suggest that face-mask ventilation, direct laryngoscopy, and tracheal intubation may be difficult. Until confirmation that lung ventilation can be maintained, either with face-mask or following tracheal intubation, spontaneous respiration should be maintained. Vascular access and positioning may be difficult because of joint contractures. Special care must be taken to ensure temperature control, especially in Type II (Stüve-Wiedemann Syndrome).

Pharmacological implications

Succinylcholine should be used with caution or simply avoided in the presence of a myopathy because of the risk of hyperkalemia and malignant hyperpyrexia. Monitor neuromuscular function when using nondepolarizing muscle relaxant.

Other conditions to be considered

• Stüve-Wiedemann Syndrome (☞Schwartz-Jampel Syndrome Type II; Schwartz-Jampel Syndrome Neonatal Form; Stüve-Wiedemann-Schwartz-Jampel Syndrome): Characterized by congenital bowing of the long bones, short stature, camptodactyly with ulnar deviation, and contractures ...