Ban M, Caillier S, Mero IL, Myhr KM, Celius EG, Aarseth J, Torkildsen O, Harbo HF, Oksenberg J, Hauser SL, Sawcer S, Compston A. No evidence of association between mutant alleles of the CYP27B1 gene and multiple sclerosis. Ann Neurol. 2012 doi: 10.1002/ana.23833. [Epub ahead of print]
An association has previously been reported between susceptibility to multiple sclerosis and the rare mutant alleles of the CYP27B1 gene responsible for autosomal recessive vitamin D-dependent rickets type 1 (VDDR1). In an attempt to replicate this finding, we screened 495 multiplex families and 2,092 single affected families, together with 4,594 cases and 3,583 controls (a total of 17,073 individuals) but were unable to find any evidence supporting this putative association. Our data do not indicate that mutations responsible for VDDR1 influence the risk of developing multiple sclerosis
This study attempted to replicate an association seen in Canadian MS patients for rare variants (less than 1% of the population having them) in the gene that activates vitamin D. The Canadian study was one I was involved in, and thus this is disappointing to see.
There are a number of explanations- firstly the Canadian study could have been a false positive- this is sadly seen quite frequently in science- see paper by