TY - JOUR
T1 - Mutational spectrum and genotype-phenotype correlations in mevalonate kinase deficiency
AU - Mandey, Saskia H. L.
AU - Schneiders, Marit S.
AU - Koster, Janet
AU - Waterham, Hans R.
PY - 2006
Y1 - 2006
N2 - Mevalonate kinase deficiency (MKD) is an autosomal recessive autoinflammatory disorder caused by mutations in the MVK gene resulting in deficient activity of mevalonate kinase (MK). Depending on the clinical severity, MKD may present as hyper-IgD and periodic fever syndrome (HIDS) or the more severe mevalonic aciduria (MA). We analyzed the MVK gene in 57 patients with MKD and found 39 different mutations including 15 novel mutations, expanding the total mutational spectrum of MKD to 63 mutations. To get more insight into the genotype-phenotype correlation in MKD, we studied the effect of selected missense mutations on MK protein stability and activity in various patient fibroblast cell lines. All MKD cell lines showed markedly decreased MK activities that correlated well with the clinical severity and, for most of the cell lines, with the amount of MK protein. When fibroblasts of MKD patients were cultured under conditions known to promote a more controlled protein folding, all cell lines of patients with the HIDS phenotype and few cell lines of patients with the MA phenotype showed an increase in the residual MK activity. This increase in enzyme activity correlates well with an increase in the MK protein levels in these cell lines, indicating that most of the mutations in MKD affect stability and/or folding of the MK protein rather than affecting the catalytic properties of the enzyme. The finding that the residual activity in MKD can be manipulated by environmental conditions may offer therapeutic options to alleviate or prevent the clinical symptoms associated with MKD
AB - Mevalonate kinase deficiency (MKD) is an autosomal recessive autoinflammatory disorder caused by mutations in the MVK gene resulting in deficient activity of mevalonate kinase (MK). Depending on the clinical severity, MKD may present as hyper-IgD and periodic fever syndrome (HIDS) or the more severe mevalonic aciduria (MA). We analyzed the MVK gene in 57 patients with MKD and found 39 different mutations including 15 novel mutations, expanding the total mutational spectrum of MKD to 63 mutations. To get more insight into the genotype-phenotype correlation in MKD, we studied the effect of selected missense mutations on MK protein stability and activity in various patient fibroblast cell lines. All MKD cell lines showed markedly decreased MK activities that correlated well with the clinical severity and, for most of the cell lines, with the amount of MK protein. When fibroblasts of MKD patients were cultured under conditions known to promote a more controlled protein folding, all cell lines of patients with the HIDS phenotype and few cell lines of patients with the MA phenotype showed an increase in the residual MK activity. This increase in enzyme activity correlates well with an increase in the MK protein levels in these cell lines, indicating that most of the mutations in MKD affect stability and/or folding of the MK protein rather than affecting the catalytic properties of the enzyme. The finding that the residual activity in MKD can be manipulated by environmental conditions may offer therapeutic options to alleviate or prevent the clinical symptoms associated with MKD
U2 - https://doi.org/10.1002/humu.20361
DO - https://doi.org/10.1002/humu.20361
M3 - Article
C2 - 16835861
SN - 1059-7794
VL - 27
SP - 796
EP - 802
JO - Human mutation
JF - Human mutation
IS - 8
ER -