Fig. 3. Activity of phosphomannomutase (PMM2) and ratio to control enzyme phosphomannose isomerase (PMM2/PMI) analyzed in cultivated fibroblasts in group of patients and controls. Due to non-normality of the observed data, non-parametric statistical methods were used. Differences between patients and controls (resp. heterozygotes and controls) were subject to Wilcoxon two sample tests. P-values less than 0.05 were considered as statistically significant. Analyses were conducted using R statistical package, version 3.1.2, R Core Team (2014).