Abstract:

Mutations in LMNA cause wide variety of disorders including Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy, and congenital muscular dystrophy. We recently found a LMNA mutation in a patient who was previously diagnosed as infantile onset inflammatory myopathy. In this study, we screened for LMNA mutations in 20 patients suspected to have inflammatory myopathy with onset at 2years or younger. The diagnosis of inflammatory myopathy was based on muscle pathology with presence of perivascular cuffing and/or endomysial/perimysial lymphocyte infiltration. We identified heterozygous LMNA mutations in 11 patients (55%), who eventually developed joint contractures and/or cardiac involvement after the infantile period. Our findings suggest that LMNA mutation should be considered in myopathy patients with inflammatory changes during infancy, and that this may help avoid life-threatening events associated with laminopathy.

日本語要旨:

LMNA変異は様々な疾患の原因と成る。我々は、LMNA変異による乳児期発症ミオパチーでは筋炎と鑑別困難な炎症性の筋病理変化を高頻度に見出すことを明らかにした。ステロイド治療に反応する例も半数に認められた。経過を追うにつれ、心症状、関節拘縮などの症状もみいだされ、LMNA変異による筋ジストロフィーの特徴を満たすようになる。乳児筋炎ではLMNA変異の有無を確認することが、予後規定因子である心症状の早期発見につながり、重要である。