Alpers-Huttenlocher Syndrome: A Rare and Devastating Mitochondrial Disorder
Introduction Alpers-Huttenlocher Syndrome (AHS) is a rare, progressive, and severe neurodegenerative disorder that typically manifests in infancy or early childhood. It is caused by mutations in the POLG gene , which encodes the catalytic subunit of the mitochondrial DNA polymerase, an enzyme critical for the replication and repair of mitochondrial DNA. Dysfunction in this enzyme leads to mitochondrial DNA depletion, impairing energy production in highly energy-dependent organs, such as the brain and liver. As a result, AHS is classified as a mitochondrial DNA depletion syndrome , characterized by a significant reduction in mitochondrial DNA in affected tissues. Key Features of Alpers-Huttenlocher Syndrome AHS is primarily recognized by its triad of symptoms: refractory seizures, developmental regression, and liver failure. Below are its hallmark clinical features: 1. Seizures (Epilepsy): Seizures are often the earliest and most prominent symptom of AHS. These seizures may be difficul...