Congenital Myopathy: Central core disease

Hypotonia, poor feeding, high arched palate, delayed motor milestones, joint contractures, resp probs, pectus carinatum (bird chest)

Autosomal dominant dz caused by point mutations of the ryanodine receptor gene on 19q, encoding the Ca-release channel of the sarcoplasmic reticulum of skeletal muscle; mutations of this gene also account for some cases of
inherited malignant hyperthermia

Autosomal dominant defect in ryanodine

Asymptomatic but affected mother –> drastic increase in trinucleotide rpts

Nl CK because not a lot of muscle degen/regen
Histology? Central cores appear as central/ eccentric areas of muscle fibers w/o oxidative enzyme activity

none

Known association w/ malignant hyperthermia- fever, muscle rigidity/necrosis, lactic acidosis (excessive Ca release)

Diagnosis is impt in case patient needs surgery ever- need to be aware of risk for malignant hyperthermia w/ anesthesia