Clinical and Pathological Heterogeneity of Korean Patients with CAPN3 Mutations

PURPOSE: This study was designed to investigate the characteristics of Korean patients with calpainopathy. MATERIALS AND METHODS: Thirteen patients from ten unrelated families were diagnosed with calpainopathy via direct or targeted sequencing of the CAPN3 gene. Clinical, mutational, and pathological spectra were then analyzed. RESULTS: Nine different mutations, including four novel mutations (NM_000070: c.1524+1G>T, c.1789_1790inA, c.2184+1G>T, and c.2384C>T) were identified. The median age at symptom onset was 22 (interquartile range: 15-28). Common clinical findings were joint contracture in nine patients, winged scapula in four, and lordosis in one. However, we also found highly variable clinical features including early onset joint contractures, asymptomatic hyperCKemia, and heterogeneous clinical severity in three members of the same family. Four of nine muscle specimens revealed lobulated fibers, but three showed normal skeletal muscle histology. CONCLUSION: We identified four novel CAPN3 mutations and demonstrated clinical and pathological heterogeneity in Korean patients with calpainopathy.

Limb-girdle muscular dystrophy type 2A in Brazilian children / Distrofia muscular cinturas tipo 2A em crianças brasileiras

ABSTRACT Calpainopathy is an autosomal recessive limb girdle muscular dystrophy (LGMD2A) caused by mutations in CAPN3 gene. Objective To present clinical and histological findings in six children with a molecular diagnosis of LGMD2A and additionally the MRI findings in two of them. Method We retrospectively assessed medical records of 6 patients with mutation on CAPN3 gene. Results All patients were female (three to 12 years). The mean of age of disease onset was 9 years. All of them showed progressive weakness with predominance in lower limbs. Other findings were scapular winging, joint contractures and calf hypertrophy. One female had a more severe phenotype than her dizygotic twin sister that was confirmed by muscle MRI. Muscle biopsies showed a dystrophic pattern in all patients. Conclusion In this cohort of children with LGMD2A, the clinical aspects were similar to adults with the same disorder.

RESUMO Calpainopatia é uma distrofia muscular de cinturas autossômica recessiva (LGMD2A) causada por mutações no gene CAPN3. Objetivo Apresentar os aspectos clínicos e histológicos em seis crianças com diagnostico molecular de LGMD2A e adicionalmente os achados na RNM de músculo em duas delas. Método Nos retrospectivamente analisamos os dados de prontuário de seis crianças com mutações no gene CAPN3. Resultados Todos os pacientes eram do sexo feminino (3 a 12 anos). A média de idade de inicio da doença foi de nove anos. Todos mostraram uma fraqueza progressiva com predomínio nos membros inferiores. Outros achados incluíam escapula alada, contratura de tendão de Aquiles e hipertrofia de panturrilhas. Uma menina apresentou um fenótipo mais severo quando comparado a sua irmã gêmea dizigótica o que foi confirmado pelos achados encontrados na RNM de músculo. Em todos os pacientes a biópsia muscular mostrou um padrão distrófico. Conclusão Nesta coorte de crianças com LGMD2A, os aspectos clínicos foram bastante similares a pacientes adultos com a mesma doença.