Asymptomatic hyperCKemia in children. Central core disease with non-diagnostic muscle biopsy

Introduction: persistently elevated serum creatine kinase levels may lean the first manifestation of an underlying neuromuscular disease. Its appropriate approach allows an adequate early treatment, a genetic counselling and information concerning complications and prognosis.

Case description: our patient was an asymptomatic 7-year-old boy with persistent serum CK elevation. He had a normal physical examination. After a normal metabolic study, a specific genetic study for dystrophinopaties or other myopathies was requested. A variant of uncertain significance mutation [RYR1, c.9912C>A; p. (Cys3304*)] associated with central core disease (#MIM11700) was obtained. Before this genetic diagnosis the invasive testing was rejected.

Discussion: central core disease is the most frequent congenital neuromuscular disease. About 90% of cases are linked to RYR1 gene mutations. RYR1 protein is a part of macromolecular complex deputed to excitation-contraction coupling through Ca²⁺ channels. Its diagnosis is confirmed by histological examination. CCD is associated to malignant hyperthermia and rabdomiolisis susceptibility.