<prompt> MELAS is an inherited condition which occurs due to deficiency ofComplex IComplex IIComplex IIIAll the above  <response>: MELAS mitochondrial encephalopathy, lactic acidosis, and stroke is an inherited condition due to NADH-Q oxidoreductase Complex I or cytochrome oxidase Complex IV deficiency. It is caused by a mutation in mitochondrial DNA and may be involved in Alzheimer disease and diabetes mellitus. Reference: Harper; 30th edition; Page no: 135 