SHMT2 and neurodevelopmental disorder: Interestingly, PYCR2 deficiency leads to neurodegeneration mediated via the upregulation of Serine hydroxymethyltransferase 2 (SHMT2), associated with neurodevelopmental disorders with cardiomyopathy, spasticity and brain abnormalities, campylobacteriosis, and a subsequent high-level concentration of glycine in the brain [57].