POLG-related disorders and their neurological manifestations

Area of Science:

• Genetics and Molecular Biology
• Neurology
• Mitochondrial Biology

Background:

• The POLG gene encodes mitochondrial DNA polymerase, crucial for mitochondrial genome replication.
• Mutations in POLG are the leading cause of inherited mitochondrial disorders, with up to 2% of the population carrying these mutations.
• These mutations result in a spectrum of phenotypes, including early-onset mtDNA depletion syndromes and later-onset mtDNA deletion syndromes.

Purpose of the Study:

• To review the clinical features, pathophysiology, natural history, and treatment of POLG-related disorders.
• To highlight the neurological manifestations of these conditions.
• To provide a comprehensive overview of inherited mitochondrial disorders caused by POLG gene mutations.

Main Methods:

• Literature review of POLG-related disorders.
• Analysis of clinical features and pathophysiology.
• Focus on neurological aspects and treatment strategies.

Main Results:

• POLG mutations cause a continuum of overlapping phenotypes with variable onset.
• Six leading disorders are identified: Alpers-Huttenlocher syndrome, childhood myocerebrohepatopathy spectrum, myoclonic epilepsy myopathy sensory ataxia, ataxia neuropathy spectrum, AR-PEO, and AD-PEO.
• Neurological manifestations are a key feature across the spectrum of POLG-related disorders.

Conclusions:

• POLG-related disorders represent a significant burden of inherited mitochondrial disease.
• Understanding the clinical spectrum and pathophysiology is crucial for diagnosis and management.
• Further research into treatment strategies, particularly for neurological symptoms, is warranted.