NFU1 and multiple mitochondrial dysfunctions syndrome 1: Although almost all NFU1 pathogenic mutations described so far are located in the C-terminal NifU [Fe‐S] cluster binding domain [23], the NFU1 p.R21P mutation located in the N-domain, which is only 4 aa apart from p.M25K and affects the mitochondrial target signal [24], has been described in the only MMDS patient showing renal tubular impairment [23,25].