Here we describe the clinical features and diagnostic workup of an infant who presented with an early onset severe encephalopathy resulting from combined deficiencies of OXPHOS due to recessive mutations (including one novel variant) in a nuclear gene (GFM1), encoding mitochondrial translation elongation factor G1 (mtEFG1) and compare these findings with other reported cases. This evidence concerns the gene GFM1 and Encephalopathy.