GNE and myopathy: There is good evidence that this variant is pathogenic including: (1) the number of patients, since 179 compound heterozygous patients carrying this variant and another variant were identified; (2) the in vitro epimerase activity of the GNE short isoform with a corresponding mutation is approximately 18% of that of wild-type GNE13; and (3) a transgenic mouse model expressing human GNE with a corresponding mutation recapitulated GNE myopathy phenotypes14.