This panel consists of 23 nuclear-encoded genes that have been associated with mitochondrial DNA depletion disorders. These nuclear genes are responsible for the maintenance of mitochondrial DNA, so dysfunction of this process can lead to multisystem involvement and tend to be progressive. Variants of these disorders include encephalomyopathic, myopathic, hepatocerebral, and neurogastrointestinal types. Common symptoms may include the following: muscle weakness/hypotonia; motor and developmental delays in early-onset cases; digestive problems such as IBS, diarrhea, and constipation or other dysmotility; neurological issues such as migraines, seizures, and strokes; dysautonomia; kidney disease, cardiomyopathy; liver disease; vision problems, especially ophthalmoplegia, and hearing loss; and fatigue. While the majority of nuclear mitochondrial disorders are inherited in an autosomal recessive pattern, some conditions demonstrate autosomal dominant inheritance. These conditions can occur in infancy or early childhood and typically have a poor prognosis. However, tremendous clinical variability exists among these disorders.
List of Genes and Conditions