NFU1 and lactic acidosis: Since now three reports have described 14 patients belonging to 11 families with NFU1 mutations (Cameron et al., 2011; Navarro-Sastre et al., 2011; Nizon et al., 2014): most cases presented with infantile encephalopathy associate with pulmonary hypertension, lactic acidosis, hyperglycinemia and severe regression leading to death before the age 15 months (Cameron et al., 2011; Navarro-Sastre et al., 2011).