[MIM 117 000]

( Central axis myopathy, Shy-McGee syndrome)

Incidence : 1-9/ 1.106. It is the only muscle disease that is very often (25 %) associated with malignant hyperthermia. Myopathy with autosomal dominant transmission, incomplete penetrance and variable expression of a mutation of the RYR1 gene on 19q13.1-13.2. coding for a receptor of the ryanodyne It is a Ca++ channelopathy at the level of the sarcoplasmic reticulum of the muscle. 

Type I muscle fibers are affected: the 0'core' are circular well-circumscribed areas at the level of the sarcomere located in the middle of the cell and that are not stained  by the usual dyes because they do not contain mitochondria, glycogen and sarcoplasmic reticulum.

'Cores' can be found at histologic examination in other muscle diseases : nemaline rod myopathy (ACTA1 or TNNT1 gene), (SELENON gene), transient multiminicore myopathy (autosomal recessive transmission of a mutation of RYR1),  minicore myopathy (SEPN1 gene) or familial hypertrophic cardiomyopathy (MYH7 gene).

The core-rod myopathy is a variant of central core myopathy caused by mutation of either the NEB gene that encodes for nebuline, of the RYR1 gene or of the KBTBD13 gene.

Other forms of central core disease are due to the autosomaml recessive transmission of  a mutation in the gene of MYH 7 (14q11.1) (coding for the  heavy chain of the cardiac β-myosin) on 14q11.1.  These mutations are however more often associated with a familial hypertrophic cardiomyopathy.

Two forms:

-         typical form: hypotonia at birth (few movements in utero) or muscle weakness in early childhood; sometimes onset in adolescence with symptoms similar to a slowly progressive limb-girdle muscle dystrophy. Retarded acquisition of the walking. Sometimes, cramps and facial hypotonia. Congenital dislocation of the hip, scoliosis, deformation of the feet. Sometimes paucisymptomatic with CK high level. 

-         severe form: fetal akinesia and major neonatal hypotonia

Anesthetic implications: 

susceptibility to malignant hyperthermia.

References : 

• Eng G, Epstein BS, Engel K, McKay D, McKay R. 
  Malignant hyperthermia and central core disease in a child with congenital dislocated hips. 
  Arch Neurol 1978; 35: 189-97.
• Krivosic-Horber R, Krivosic I. 
  Myopathie à axe central (central core disease) associée à une sensibilité à l’hyperthermie maligne. 
  La Presse Médicale 1989 ; 18 : 828-31.
• Otsuka H, Komura Y, Mayumi T, Yamamura T, Kemmotsu O, Mukaida K. 
  Malignant hyperthermia during sevoflurane anesthesia in a child with central core disease.
  Anesthesiology 1991; 75:699-701.
• Curran JL, Hall WJ, Halsall PJ, Hopkins PM et al. 
  Segregation of malignant hyperthermia, central core disease and chromosome 19 markers.
  Br J Anaesth 1999; 82: 217-22.
• Klingler W, Rueffert H, Lehmann-Horn F, Girard T, Hopkins PM. 
  Core myopathies and risk of malignant hyperthermia. 
  Anesth Analg 2009; 109: 1167-73.
• Brislin RP, Theroux MC. 
  Core myopathies and malignant hyperthermia susceptibility : a review. 
  Pediatr Anesth 2013 ; 23 : 834-41.
• Christiaens F, Van den Bergh PYK. 
  Les myopathies congénitales. 
  Louvain Med 2014 ; 133 : 478-90.
• North K, Wang C, Clarke N, Jungbluth H, Vainzof M, Dowling J et al. 
  Approach to the diagnosis of congenital myopathies. 
  Neuromuscul Disord 2014 ; 24 : 97-116.

Updated: June 2021