<b><i>BAG3</i>-Related Myofibrillar Myopathy Presenting as Hypercapnia: A Case Report and Literature Review</b>

Abstract

Objective BAG3-related myopathy is a rare condition so far reported in twenty patients worldwide. The purpose of this study was to draw attention to this rare disease and to the fact that BAG3-related myopathy should be considered as a rare differential diagnosis of hypercapnia. MethodsWe report a sporadic case of a 14-year-old Chinese girl with a de novo p.Pro209Leu mutation in BAG3 and reviewed the literatures for reported cases related to this mutation. ResultsWe described a 14-year-old Chinese girl who presented with gradually appearing symptoms of hypercapnia that required assisted ventilation.The muscle biopsy and the blood whole-exome sequencing results confirmed the diagnosis of myofibrillar myopathy with a de novo p.Pro209Leu mutation in BAG3. Totally twenty-one patients from twenty families with a confirmed diagnosis of BAG3-related myopathy were reported to date, including this patient and literature review. The male to female ratio was 11:10 and most showed initial symptoms in the first decade of life. Most patients presented toe/clumsy walking or running as the onset symptom, followed by muscle weakness or atrophy. Creatine kinase levels were