%0 Case Reports
%T An early onset benign myopathy with glycogen storage caused by a de novo 1.4 Mb-deletion of chromosome 14.
%A Severa G
%A Pennisi A
%A Barnerias C
%A Fiorillo C
%A Scala M
%A Taglietti V
%A Cojocaru AI
%A Jouni D
%A Tosca L
%A Tachdjian G
%A Desguerre I
%A Authier FJ
%A Carlier RY
%A Metay C
%A Verebi C
%A Malfatti E
%J Neuromuscul Disord
%V 33
%N 10
%D 2023 Oct 25
%M 37743183
%F 3.538
%R 10.1016/j.nmd.2023.08.011
%X Early onset myopathies are a clinically and histologically heterogeneous monogenic diseases linked to approximately 90 genes. Molecular diagnosis is challenging, especially in patients with a mild phenotype. We describe a 26-year-old man with neonatal hypotonia, motor delay and seizures during infancy, and non-progressive, mild muscular weakness in adulthood. Serum Creatine kinase level was normal. Whole-body muscle MRI showed thin muscles, and brain MRI was unremarkable. A deltoid muscle biopsy showed glycogen storage. WGS revealed a de novo 1.4 Mb-deletion of chromosome 14, confirmed by Array-CGH. This microdeletion causes the loss of ten genes including RALGAPA1, encoding for RalA, a regulator of glucose transporter 4 (GLUT4) expression at the membrane of myofibers. GLUT4 was overexpressed in patient's muscle. Here we highlight the importance to search for chromosomal alterations in the diagnostic workup of early onset myopathies.