Skin rush during summer or uterine stiffness during pregnancy orient toward LDHA mutations; bifid uvula and hepatopathy are described in Phosphoglucomutases 1 (PGM1)-associated myopathy (GSD XIV); recessive mutations in the ENO3 gene cause GSD XIII or muscle β-enolase deficiency; phenotype elicited by strenuous exertion and isometric muscle activity is usually milder than GSD V and “second wind” phenomenon is not observed (60–62, 64). This evidence concerns the gene PGM1 and myopathy.