Defects in the mitochondrial [4Fe-4S] protein assembly impact numerous metabolic pathways, and depending on the affected Fe/S protein, the assembly factors are grouped into one of five types of multiple mitochondrial dysfunction syndromes (MMDS) (Lill and Freibert, 2020; Lebigot et al., 2021; Camponeschi et al., 2022), such as MMDS3 caused by mutations in IBA57 (OMIM 615330) (Ajit Bolar et al., 2013; Debray et al., 2015; Lossos et al., 2015). The gene discussed is IBA57; the disease is Fatal multiple mitochondrial dysfunction syndrome type 2.