C9ORF72 hexanucleotide repeat expansion: From ALS and FTD to a broader pathogenic role?

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• The C9ORF72 gene is the most common genetic cause of monogenic amyotrophic lateral sclerosis (ALS) and fronto-temporal dementia (FTD).
• The pathogenic mechanism involves a hexanucleotide repeat expansion (HRE) in the C9ORF72 gene, leading to various downstream cellular dysfunctions.
• Understanding the genotype-phenotype correlations and disease mechanisms is crucial for developing effective therapeutic strategies.

Purpose of the Study:

• To provide a comprehensive update on recent clinical, biological, and therapeutic advancements related to C9ORF72.
• To elucidate the genotype-phenotype correlations in C9ORF72-associated neurological disorders.
• To explore the molecular mechanisms underlying neuronal death in C9ORF72-related diseases and potential therapeutic avenues.

Main Methods:

• Literature review of recent studies on C9ORF72 gene mutations.
• Analysis of clinical data, genetic findings, and biological mechanisms.
• Synthesis of current understanding of genotype-phenotype relationships and therapeutic strategies.

Main Results:

• The C9ORF72 HRE is associated with a spectrum of neurological phenotypes beyond classical ALS and FTD.
• Detailed insights into the molecular pathways contributing to neurodegeneration in C9ORF72 carriers.
• Emerging therapeutic strategies targeting the C9ORF72 mutation and its consequences.

Conclusions:

• C9ORF72 hexanucleotide repeat expansions represent a significant genetic factor in neurodegenerative diseases.
• Further research is needed to fully understand the diverse clinical presentations and underlying pathobiology.
• Therapeutic interventions targeting C9ORF72 hold promise for patients with these devastating neurological conditions.