Genotype-phenotype Correlation for Non-HLA Disease Associated Risk Alleles in Multiple Sclerosis

Background: Recent advances in MS genetics have led to the successful identification of a number of novel disease associated non-HLA genes. It is now becoming possible to begin to analyse the possible effects of these genes on aspects of disease phenotype where longitudinal clinical data is available.

Objective: We examined phenotypic impact of 10 non-HLA disease associated single nucleotide polymorphisms (SNPs) in 1003 patients with MS followed for an average of 14.1 years.

Methods: Association of SNPs with time to established disability milestones (Expanded Disability Status Scale (EDSS) 4.0, 6.0, 8.0), onset of secondary progression and cross-sectional aspects of early phenotype were tested using survival analysis.

Results: No SNP was associated with systematic deflection in time to disability milestones, age at onset or time to secondary progression.

Conclusions: Genotypic information from non-HLA associated SNPs is unlikely to inform individual patient prognosis in the clinical setting although minor phenotypic effects operative at specific phases of disease cannot be excluded. This preliminary study provides a framework for future genotype-phenotype analysis in MS and will need to be replicated in independent patient cohorts.