X-linked myopathy with excessive autophagy: a case report and literature review / 中华神经科杂志

ABSTRACT

Objective:To report a case of X-linked myopathy with excessive autophagy (XMEA) and review the literature aiming to analyze the clinical manifestations, muscle imaging, muscle pathology and genetic characteristics of the disease.Methods:The medical history, physical and laboratory examination, muscle imaging and pathology, and genetics of a patient with XMEA who was admitted to QiLu Hospital of Shandong University in June 2018 were retrospectively collected. PubMed, CNKI, and Wanfang Data were searched for relevant literature.Results:This patient was a 40-year-old male who complained of hyper creatine kinase and weakness in his lower extremities for 4 years. Since elementary school, his heels could not touch the ground when squatting and his motor performance was inferior to his peers. Abnormal creatine kinase levels (320-1 167 U/L) were identified several times prior to admission. Magnetic resonance imaging of lower extremities revealed symmetrical fat replacement in bilateral lateral femoral muscles, adductor major and medial head of the gastrocnemius. Muscle biopsy showed intrafibrillar autophagic vacuoles with sarcolemmal features as well as membrane attack complex depositing on the vacuolar membrane; genetic analysis confirmed a hemizygous mutation c. *6A>G in VMA21 gene. Searching the literature, it was found that the onset age of XMEA patients varied from newborns to adulthood. Those XMEA patients with childhood or adulthood-onset mostly exhibited muscle weakness and (or) atrophy in the proximal limbs, with slow progression and normal life expectancy, while those with infant onset were prone to multiple system involvement, rapid disease progression, and high risk of death. Conclusions:XMEA is an extremely rare hereditary autophagic vacuolar myopathy. Although the clinical and prognostic manifestations of XMEA patients vary greatly among different age groups, the muscle pathological changes are relatively consistent, and genetic testing is the main diagnostic method for this disease.