Complex Genetic Framework in Familial Amyotrophic Lateral Sclerosis With a C9ORF72 Mutation: A Case Report

Area of Science:

• Genetics
• Neurology
• Oncology

Background:

• Amyotrophic lateral sclerosis (ALS) presents significant clinical heterogeneity, complicating drug development.
• Previous research suggested sporadic ALS (sALS) heterogeneity stems from polygenic factors and linked gene mutations.
• This study investigated if familial ALS (fALS) also exhibits a complex genetic framework.

Observation:

• Post-mortem genetic screening of a familial ALS patient with a C9ORF72 mutation was performed using whole exome sequencing (WES).
• Rare pathological variants (MAF ≤ 0.01) were identified, supporting a complex genetic basis in fALS.
• Low-frequency variants (0.01 < MAF < 0.05) in AHNAK2, GLI3, PTIRM1, and ZNF254 were also found.

Findings:

• The genetic screening confirmed a complex genetic framework in familial ALS, extending beyond the C9ORF72 mutation.
• These additional genetic variants may act as C9ORF72 modifiers in fALS.
• A link between these variants and neuromuscular disorders, ALS, and cancer was observed.

Implications:

• Whole exome sequencing (WES) could enhance the diagnosis and personalized treatment strategies for ALS patients.
• Identifying complex genetic interactions is crucial for developing effective disease-modifying drugs for ALS.
• Further research into these genetic modifiers may uncover novel therapeutic targets for ALS and related conditions.