Clinicians, researchers, industry and patient group representatives (in total 25 members of the study group from 12 countries) gathered in Hooffdorp in September 2018 to discuss current knowledge and perspective research in GNE myopathy (previously known as Nonaka disease, Quadriceps Sparing Myopathy, Distal Myopathy with Rimmed Vacuoles or Hereditary inclusion body myopathy type 2). GNE myopathy is an -rare autosomal recessive disease caused by bi-allelic mutations in the GNE gene (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase). The phenotype was described in 1980’s under different names, and the disease-causing gene, together with the Middle Eastern founder mutation, was described over 10 years ago [1], [2]. Since then knowledge about molecular mechanism of the disease, phenotypic variability and epidemiology has expanded significantly. A recent Phase 3 clinical trial conducted by Ultragenyx Pharmaceutical did not show a beneficial effect of sialic acid supplementation on muscle strength, which highlighted the need for a deeper understanding of the pathophysiology of the disease and exploring other therapeutic approaches.

The aims of this workshop were: to achieve a better understanding of GNE myopathy epidemiology, pathophysiology, phenotype and genetics; to discuss the strength and weakness of the current animal models; to discuss genotype-phenotype correlations; to agree on standards of care for GNE myopathy; to discuss clinical trial readiness and data collection; to agree on functional scale for GNE myopathy assessment; and to explore novel ways for a better understanding of the pathophysiology of GNE myopathy.