P.11 Clinical, pathological, imaging, and genetic characterization in a Taiwanese cohort with congenital myopathy

Abstract

Congenital myopathy (CMP) is a genetically heterogeneous, hereditary disease entity characterized by clinically infantile hypotonia with facial weakness and histologically specific changes. The disease severity ranges from neonatal onset with respiratory failure to mild weakness with stationary course. This study aims to analyze the phenotypes and genotypes in Taiwanese patients with CMP in a referral center for neuromuscular diseases (NMDs). We enrolled 89 patients clinically suspected of having CMP who underwent muscle biopsy with subsequent genetic analysis in the past 15 years. Based on pathological features, we categorized the patients into nemaline myopathy, central core disease, multiminicore disease, congenital myopathy with uniform type 1, centronuclear myopathy, congenital fiber type disproportion, neuropathic change and others, respectively. Subsequent sequencing of target genes or panel for NMDs done in 65 patients and identified mutations in <i>ACTA1, NEB, KLHL40, RYR1, SEPN1, MEGF10, DNM2, MTM1, TPM2</i> and other genes unrelated to CMP. Our study revealed that RYR1-related myopathy counted for the largest proportion of CMP in Taiwan. As the causative genes of CMP are often big and benign polymorphism might be frequently identified, muscle pathology still plays an important role to support the final diagnosis. The domestic data could be useful by joining global registry for nature history study and future clinical trials.