To the Editor:
Juvenile idiopathic inflammatory myopathy (JIIM) refers to a group of rare chronic autoimmune conditions. Juvenile dermatomyositis (JDM) is the most common JIIM. The hallmarks of JDM are characteristic cutaneous features and proximal muscle weakness; however, adermatitic forms have been described. Polymyositis presents with both proximal and distal muscle weakness, muscle atrophy, and similar degrees of dysphagia, arthritis, and contractures1. Although magnetic resonance imaging (MRI) is widely used, muscle biopsy remains a critical tool in the diagnosis of JIIM, especially in atypical cases1.
Recently, LMNA-associated congenital muscular dystrophy (LMNA-CMD) has been reported as a novel and severe form of laminopathy with secondary inflammatory changes mimicking inflammatory myopathies2,3. Mutations in the LMNA gene encoding lamin A/C are responsible for multiple disease phenotypes4. Some of them may present early in life as a congenital muscular dystrophy2,3.
Patient
We report the case of a 26-month-old girl, first child of non-consanguineous parents, who was referred to our department based on a history of progressive muscle weakness with raised creatine kinase (CK) and a muscle biopsy showing marked inflammation. There was no family history of neuromuscular or autoimmune diseases. She was born by normal uncomplicated delivery; no reduced fetal movements were described by the mother during pregnancy. By 1 year of age, she was …
Address correspondence to Dr. E. Moraitis, Rheumatology Department, Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK. E-mail: elena.moraitis.13{at}ucl.ac.uk