Is Mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes inherited ?
How is mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) inherited? MELAS is caused by mutations in mitochondrial DNA (mtDNA) and is therefore transmitted by maternal inheritance (also called mitochondrial inheritance). This type of inheritance applies to all conditions caused by genes in mtDNA. Mitochondria are structures in each cell that turn molecules into energy, and each contain a small amount of DNA. Only egg cells (not sperm cells) contribute mitochondria to offspring, so only females can pass on mitochondrial mutations to their children. Conditions resulting from mutations in mtDNA can appear in every generation of a family and can affect both males and females. In most cases, people with MELAS inherit an altered mitochondrial gene from their mother. Less commonly, the condition results from a new mutation in a mitochondrial gene and occurs in an individual with no history of MELAS in the family.