[MIM 255 800, 142 461]

(Osteochondromuscular dystrophy, chondrodysplasic or chondrodystrophic myotonia)

Rare. Autosomal recessive transmission of a mutation of the HSPG2 gene (1p36.12) coding for perlecan, a large protein of the heparan-sulfate group: this protein is present in the basal membrane of the extracellular matrix and plays a role in regulating muscle excitability (the mutation causes the absence of acetylcholinesterase at the neuromuscular junction) and the development of cartilage, which explains both myotonia and chondrodysplasia.

Early onset. There is a continuing activity of the muscle fiber resulting in blepharophimosis, microstomia with mask-like facies, generalized stiffness and osteoarticular anomalies with a short stature. Platyspondyly and metaphyseal and epiphyseal dysplasia. Kyphoscoliosis.

Three types have been described:

-        1A: moderate bone dysplasia; late diagnosis

-        1B: diagnosed in the neonatal period with important bone dysplasia

-        2: rare, very severe with early mortality

A case of intraoperative hypermetabolic reaction similar to a crisis of malignant hyperthermia has been reported.

Anesthetic implications:

difficult intubation. Possible crises of myotonia (see Myotonic dystrophy). Avoid succinylcholine. Monitoring of curarization if using a non-depolarizingant myorelaxant: one  well documented case of rightwards displacement of the dose-response curve of the rocuronium  with significant increase in the dose required to obtain the curarization, followed by very fast decurarization.

References: 

-        Seay A, Ziter F. 
Malignant hyperpyrexia in a patient with Schwartz-Jampel syndrome.
J Pediatr 1978;93: 83-4.

-        Ray S, Rubin AP. 
Anaesthesia in a child with Schwartz-Jampel syndrome. 
Anaesthesia 1994; 49:600-2.

-         Theroux MC, Kettrick RG, Khine HH. 
Laryngeal mask airway and fiberoptic endoscopy in an infant with Schwartz-Jampel syndrome.
Anesthesiology 1995; 82: 605.

-         Eikermann M, Bredendiek M, Schaper J, Hövel M, Peters J. 
Resistance to rocuronium in a child with Schwartz-Jampel syndrome type 1. 
Neuropediatrics 2002; 33:43-6.

Updated: August 2021