RTN4IP1 Mutation and Endocrine Failure: Clinical Features and Possible Benefits of Coenzyme Q10

RTN4IP1 encodes a mitochondrial oxidoreductase essential for Coenzyme Q biosynthesis; pathogenic variants have been reported mainly in optic neuropathy and encephalopathy. We describe a 30-year-old woman carrying three novel pathogenic RTN4IP1 variants by exome sequencing (c.1163G>A p.Arg388Gln, c.949A>C p.Met317Leu, c.1109T>C p.Phe370Ser), who presented with panhypopituitarism, optic-nerve hypoplasia, corpus callosum agenesis, bicuspid aortic valve disease, seizures, and muscle pain, already on conventional hormone replacement. Coenzyme Q10 (CoQ10) (200 mg) was administered orally for six months; outcomes were assessed using BPI, WOMAC, TUG, LEFS, grip-strength dynamometry, SF-36, CPK and LDH and after six months of daily 200 mg CoQ10 the patient showed marked reductions in pain (BPI 4 → 0.8; –80 %) and muscle-damage markers (CPK 254 → 110 U/L) together with gains in grip strength (+49 %) and lower-extremity function (LEFS 31 → 60; +94 %). SF-36 domains related to physical health showed marked gains, while emotional scores remained stable. This is the first report linking RTN4IP1 mutations to endocrine failure and suggesting a therapeutic role for CoQ10 in mitochondrial-related endocrine disease.