Comment to Santos et. al., "Hyper-IgD and periodic fever syndrome: a new MVK mutation (p.R277G) associated with a severe phenotype"

We performed molecular modeling analysis onto a novel mutation in the gene MVK, described by Santos et al., found to be causative of a severe form of Hyper-IgD/Mevalonate Kinase Deficiency. The mutation p.R277G, in our analysis, lowers the binding affinity for some enzyme's substrates. Interestingly, we found that p.R277G mutation inhibits binding of Isopentenyl Pyrophosphate (IPP) (binding free energy = 0 Kcal/mol), one of isoprenoids responsible for feedback-inhibition of MVK. IPP is known to be an activator of a specific class of T-cells and we can hypothesize that increased levels of this metabolite generates an aberrant immune system response. Indeed other experiments are needed to verify this hypothesis; however, this work demonstrates usefulness of molecular modeling in generating novel pathogenic hypothesis.