This research group tested whether genetic variation is associated with multiple sclerosis lesion topology by a genome-wide association study (GWAS). The researchers tested this hypothesis by analysing the distribution of multiple sclerosis lesions and used that measure as a trait in a GWAS.
They used voxel-level 3T magnetic resonance imaging T1 weighted scans to reconstruct the 3D topology of lesions in 284 subjects with multiple sclerosis and tested if this was a heritable phenotype. They computed the first ten principal components in order to focus on lesion distribution and carried out GWAS on each of these.
The researchers found 31 significant associations with component eight, which represents variation of lesion topology in the population. The majority can be linked to genes related to immune cell function and to myelin and neural growth.
The results show how quantitative traits derived from brain MRI can be used as dependent variables in a GWAS. In the future, the integration of imaging and genetic data sets is likely to become a mainstream tool for understanding the complex biological processes of MS.
Authors: Gourraud PA, Sdika M, Khankhanian P
Source: Brain. 2013 Feb 13. [Epub ahead of print]
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