It is an autosomal recessive , developmental mitochondrial DNA depletion disorder characterized by deficiency in mitochondrial DNA polymerase gamma ( POLG ) catalytic activity , refractory seizures , neurodegeneration , and liver disease .
O O O O O O O B-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature O O O O O O B-GeneOrGeneProduct I-GeneOrGeneProduct I-GeneOrGeneProduct O B-GeneOrGeneProduct O O O O O B-DiseaseOrPhenotypicFeature O B-DiseaseOrPhenotypicFeature O O B-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature O