Thelansis

  Mitochondrial DNA (mtDNA) disorders are common inherited metabolic disorders caused by mutations in over 300 genes. These mutations can result in homoplasmy, where all copies of mtDNA are identical, or heteroplasmy, where there is a mixture of mutated and wild-type mtDNA. While homoplasmic mutations cause some diseases like LHON, most pathogenic mtDNA variants are heteroplasmic. The clinical presentation of mtDNA disease varies widely in the age of onset and combination of symptoms. Patients with a primary mtDNA disorder typically have a high percentage of a specific mtDNA mutation, around 60-80%, in clinically affected tissues. Organs and tissues that heavily rely on oxidative phosphorylation, such as skeletal and cardiac muscles and the brain, are primarily affected. Secondary mtDNA mutations, deletions, and depletion can be caused by primary nuclear gene defects that affect mtDNA maintenance and replication. These secondary mutations can cause clinical phenotypes similar to ...

 Mitochondrial DNA (mtDNA) disorders are common inherited metabolic disorders caused by mutations in over 300 genes. These mutations can result in homoplasmy, where all copies of mtDNA are identical, or heteroplasmy, where there is a mixture of mutated and wild-type mtDNA. While homoplasmic mutations cause some diseases like LHON, most pathogenic mtDNA variants are heteroplasmic. The clinical presentation of mtDNA disease varies widely in the age of onset and combination of symptoms. Patients with a primary mtDNA disorder typically have a high percentage of a specific mtDNA mutation, around 60-80%, in clinically affected tissues. Organs and tissues that heavily rely on oxidative phosphorylation, such as skeletal and cardiac muscles and the brain, are primarily affected. Secondary mtDNA mutations, deletions, and depletion can be caused by primary nuclear gene defects that affect mtDNA maintenance and replication. These secondary mutations can cause clinical phenotypes similar to pri...