No C9orf72 repeat expansion in patients with primary progressive multiple sclerosis

In this study, we screened C9orf72 in 189 Italian patients with primary progressive MS (PPMS), a rare clinical form characterized by less inflammation over neurodegenerative features. We failed to detect C9orf72 RE, but a significant representation of intermediate alleles (≥20 units) was observed in our PPMS cohort (2.1%) compared to healthy controls (0%, p<0.05). In the normal range, allele distribution showed a trimodal pattern (2,5,8-repeat units) in PPMS and healthy controls with no significant difference. Our findings further demonstrate that C9orf72 RE is not genetically associated to MS spectrum, but suggest that intermediate alleles may represent risk factors as already reported for Parkinson disease.
Source: Multiple Sclerosis and Related Disorders - Category: Neurology Source Type: research