POLG-Related Spectrum Disorders

**Semantic type:** Disease or Syndrome

**Definition:** A group of disorders with overlapping phenotypes caused by mutation(s) of the POLG gene, encoding DNA polymerase subunit gamma-1. Phenotypic variations include Alpers-Huttenlocher syndrome (AHS), childhood myocerebrohepatopathy spectrum (MCHS), myoclonic epilepsy myopathy sensory ataxia (MEMSA), ataxia neuropathy spectrum (ANS), autosomal recessive progressive external ophthalmoplegia (arPEO), and autosomal dominant progressive external ophthalmoplegia (adPEO).