A recent study published in BMC Medical Genetics (http://www.biomedcentral.com/1471-2350/11/64) has attempted to study genetic risk factors for CCSVI. The authors investigated
copy number variations (CNVs, segments of DNA that differ between people in terms of number of copies) in the HLA region (the region that confers the biggest MS genetic risk) of 15 patients with CCSVI. The authors found that the number of CNVs correlated with the number of venous malformations a patient had.
This is an interesting study, but needs to be validated in a much larger cohort of patients and healthy controls. Furthermore, it is not yet clear how CNVs in different parts of the HLA region can lead to the same CCSVI phenotype.