Use

This test is used to diagnose mitochondrial disease that is caused by point mutations or small deletions/duplications in the mtDNA. MtDNA point mutations are the most important class of variants detected by this test. While some mitochondrial disorders caused by mtDNA point mutations only affect a single organ (e.g. the eye in Leber hereditary optic neuropathy [LHON]), many involve multiple organ systems and often present with prominent neurologic and myopathic features. Mitochondrial disorders may present at any age. Many individuals with a mutation of mtDNA display a cluster of clinical features that fall into a discrete clinical syndrome, such as the Kearns-Sayre syndrome (KSS), chronic progressive external ophthalmoplegia (CPEO), mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy with ragged-red fibers (MERRF), neurogenic weakness with ataxia and retinitis pigmentosa (NARP), or Leigh syndrome (LS). However, considerable clinical variability exists, and many individuals do not fit neatly into one particular category, which is well-illustrated by the overlapping spectrum of disease phenotypes.