Identification of a Novel MTM1 Variant in a Chinese Infant with X-Linked Myotubular Myopathy - A Case Report

Abstract

Abstract X-linked Myotubular myopathy (XLMTM; MIM 310400) is a rare congenital disease with manifestations leading to respiratory failure, hypotonia and feeding difficulties. To date, an insufficient amount of MTM1 cases have been reported thus far. Herein, we report a male neonate who presented with ventilator dependency from birth. Furthermore, neonatal hypotonia, persistent lack of spontaneous breathing and motor activities raised suspicion of a neuromuscular disease at 7 days of life. Therefore, after exclusion of other possible causes, molecular genetic analysis of the patient and the parents was executed. As a result, a novel c.1180dupG/p.Asp394GlyfsTer2 (NM_000252) duplication mutation in exon 11 of the MTM1 gene was detected. The variant was assessed as likely pathogenic according to the American College of Medical Genetics and Genomics guidelines. The patient died soon after from respiratory failure. Our findings provided an insight into neonatal MTM1 disorder and further expanded the mutation spectrum of X-linked Myotubular myopathy. Importantly, provides aid in prenatal diagnosis and genetic counseling for XLMTM carriers.