RMND1 (required for meiotic nuclear division 1 homolog) encodes a nuclear-encoded mitochondrial protein essential for mitochondrial translation and respiratory chain function. The protein is required for mitochondrial translation, possibly by coordinating the assembly or maintenance of the mitochondrial ribosome 12. Biallelic pathogenic variants in RMND1 cause combined oxidative phosphorylation deficiency 11, a severe mitochondrial disorder with highly heterogeneous clinical manifestations. The disease spectrum includes white matter encephalopathy, sensorineural hearing loss, and progressive renal dysfunction with hyporeninemic hypoaldosteronism causing electrolyte imbalances 3. Renal manifestations range from chr6 kidney disease to end-stage renal failure requiring replacement therapy 45. Additional features include dilated cardiomyopathy, neurological abnormalities such as ataxia and developmental delay, and primary ovarian insufficiency in female patients 46. The phenotypic spectrum has been recently expanded to include polymicrogyria 7. The condition demonstrates significant phenotypic heterogeneity even within families, complicating treatment decisions and prognosis 5. Early recognition is crucial as some manifestations like electrolyte disturbances are treatable, though the overall prognosis remains guarded due to multi-organ involvement.