<prompt> All are mitochondrial disorders except:Pearson SyndromeMERRF Myoclonic Epilepsy Ragged Red FibreMELAS Mitochondrial Encephalopathy Lactic Acidosis and Stroke-like episodeFragile X Syndrome  <response>: d. Fragile X SyndromeRef: Nelsons 20e p 600-601, Ghai 8e p 644Mitochondrial Disorders, include Leber Hereditary Optic Neuropathy, MELAS Mitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes, MERRFMyoclonic epilepsy, ragged red fibers in muscle, Pearson syndromeExamples of Mitochondrial Disorders Mnemonic: K-L-M-N-O-PDiseasePhenotypeKSSKearn-Sayre syndromeExternal ophthalmoplegia, heart block, retinal pigmentation, ataxiaLHONLeber hereditary optic neuropathyBilateral subacute or acute painless optic atrophyMELASMitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes; may manifest only as diabetesMERRFMyoclinic epilepsy, ragged red fibres in muscle, ataxia, increased CSF protein, sensorineural deafness, dementiaNARPNeuropathy, Ataxia, Retinitis Pigmentosa, Leigh diseaseLoss of central vision leading to blindness in young adult lifeCPEOChronic progressive external OphthalmoplegiaBilateral ptosis, ophthalmoplegia proximal muscle weaknessPearson syndromePancreatic insufficiency, pancytopenia, lactic acidosis 