Two patients with GMPPB mutation: the overlapping phenotypes of limb-girdle myasthenic syndrome and limb-girdle muscular dystrophy dystroglycanopathy

Montagnese, Federica; Klupp, Elisabeth; Karampinos, Dimitrios C.; Biskup, Saskia; Gläser, Dieter; Kirschke, Jan S. und Schoser, Benedikt (2017): Two patients with GMPPB mutation: the overlapping phenotypes of limb-girdle myasthenic syndrome and limb-girdle muscular dystrophy dystroglycanopathy. In: Muscle & Nerve, Bd. 56, Nr. 2: S. 334-340

Abstract

Introduction: Mutations in the guanosine diphosphate-mannose pyrophosphorylase-B gene (GMPPB) have been identified in congenital muscular dystrophies, limb-girdle muscular dystrophy (LGMD2T), and congenital myasthenic syndromes (CMSs);overall, 41 patients have been described. Methods: Two patients presented with a myasthenic syndrome (patient 1;74 years old) and rhabdomyolysis (patient 2;23 years old). Examinations included repetitive nerve stimulation, muscle biopsy and whole-body MRI (WBMRI);next generation sequencing facilitated diagnosis. Results: We identified the following GMPPB mutations: c. 79G > C/c.859C > T in the 23-year-old man with LGMD2T-phenotype and c. 79G > C homozygosity in the 74-year-old woman with CMS phenotype. WBMRI showed fatty degeneration of paraspinal, thigh adductor, and calf muscles in patient 1 and edematous changes of the soleus muscle in patient 2. Conclusions: This case of c. 79G > C homozygosity causing a mild, late-onset CMS phenotype, confirms the mild nature of this common mutation. The descriptions of these 2 new GMPPB cases add to the knowledge regarding this recently discovered, heterogeneous disease.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0148-639X
• Sprache: Englisch