Bilateral congenital lumbar hernias in a patient with central core disease--A case report.

Congenital lumbar hernias are rare malformations caused by defects in the development of the posterior abdominal wall. A known association exists with lumbocostovertebral syndrome; however other associated anomalies, including one case with arthrogryposis, have been previously reported. We present an infant girl with bilateral congenital lumbar hernias, multiple joint contractures, decreased muscle bulk and symptoms of malignant hyperthermia. Molecular testing revealed an R4861C mutation in the ryanodine receptor 1 (RYR1) gene, known to be associated with central core disease. This is the first reported case of the co-occurrence of congenital lumbar hernias and central core disease. We hypothesize that ryanodine receptor 1 mutations may interrupt muscle differentiation and development. Further, this case suggests an expansion of the ryanodine receptor 1-related myopathy phenotype to include congenital lumbar hernias.