Required for mitochondrial translation, possibly by coordinating the assembly or maintenance of the mitochondrial ribosome (PubMed:23022098, PubMed:25604853). Homooligomer (PubMed:23022098, PubMed:25604853). May be localized in mitochondrial RNA granules (PubMed:25604853). The disease is caused by variants affecting the gene represented in this entry. Belongs to the RMD1/sif2 family.