C9orf72 and amyotrophic lateral sclerosis: However, it is noteworthy that previous studies report conflicting relationships between the frequency of RNA foci and age of disease onset70,71 and no correlation between RNA foci aggregation and cognitive decline72, suggesting that the relationship between RNA foci and the clinical manifestation of C9orf72 ALS may be nuanced, context-specific, and perhaps less linked to cognitive function.