Predicted PRODH residual activity was evaluated for each genotype according to the functional data published by Bender et al.23. Mutations with severe effect on PRODH activity appear in bold, mutations with moderate effect in normal character and mutations with unknown effect in italic. Abnormal plasma proline values appear in bold. Fasting abnormal plasma proline values: age >18 years: males > 377 μmol/L, females > 316 μmol/L; 5 years>age <18 years: > 270 μmol/L; age < 5 years: > 235 μmol/L.