The metabolic decompensation may be life-threatening with encephalopathy and hyperammonemia [8], and neither clinical symptoms nor biochemical findings allow distinguishing RFVT1 deficiency from MADD deficiency (caused by biallelic ETFA, ETFB and ETFDH variants). This evidence concerns the gene SLC52A1 and hyperinsulinemic hypoglycemia, familial, 4.