Our study increases the range of clinical presentations associated with mutations in POLG gene, underlining some peculiar clinical features, such as PEO associated with corneal edema, and epilepsy, severe neuropathy with achalasia.
Syndromic mitochondrial disorders obligatory associated with epilepsy include Alpers-Huttenlocher-syndrome (AHS), ataxia neuropathy spectrum (ANS), Leigh-syndrome, MELAS-syndrome, myoclonic epilepsy, myopathy, and sensory ataxia (MEMSA) syndrome, and MERRF-syndrome, Occasionally, epilepsy is a phenotypic feature in IOSCA, KSS, LHON, LBSL, or NARP, All types of seizures occur but most frequently generalized tonic-clonic seizures, partial seizures, myoclonic jerks, or West-syndrome was reported.
Several recent studies identified common genetic and molecular substrates for migraine and epilepsy, including phenotypic-genotypic correlations with mutations in the CACNA1A, ATP1A2, and SCN1A genes, as well as in syndromes due to mutations in the SLC1A3, POLG, and C10orF2 genes.
Whereas PEO1 mutations were not found in our cohort, POLG frequently caused ataxia with PEO (47%), psychiatric comorbidities (20%) and, more rarely, with epilepsy (14%).