TY - JOUR
T1 - Heterozygous mutations in GTP-cyclohydrolase-1 reduce BH4 biosynthesis but not pain sensitivity
AU - Nasser, Arafat
AU - Møller, Anette Torvin
AU - Hellmund, Vibe
AU - Thorborg, Sidsel Salling
AU - Jespersgaard, Cathrine
AU - Bjerrum, Ole J.
AU - Dupontd, Erik
AU - Nachman, Gösta
AU - Lykkesfeldt, Jens
AU - Jensen, Troels Staehelin
AU - Møller, Lisbeth Birk
PY - 2018
Y1 - 2018
N2 - Human studies have demonstrated a correlation between noncoding polymorphisms of "the pain protective" haplotype in the GCH1 gene that encodes for GTP cyclohydrolase I (GTPCH1)-which leads to reduced tetrahydrobiopterin (BH4) production in cell systems-and a diminished perception of experimental and clinical pain. Here, we investigate whether heterozygous mutations in the GCH1 gene which lead to a profound BH4 reduction in patients with dopa-responsive dystonia (DRD) have any effect on pain sensitivity. The study includes an investigation of GCH1-associated biomarkers and pain sensitivity in a cohort of 22 patients with DRD and 36 controls. The patients with DRD had, when compared with controls, significantly reduced levels of BH4, neopterin, biopterin, and GTPCH1 in their urine, blood, or cytokine-stimulated fibroblasts, but their pain response with respect to non-painful stimulation, (acute) stimulus-evoked pain, or pain response after capsaicin-induced sensitization was not significantly different. A family-specific cohort of 11 patients with DRD and 11 controls were included in this study. The patients with DRD were heterozygous for the pain protective haplotype in cis with the GCH1 disease-causing mutation, c.899T.C. No effect on pain perception was observed for this combined haplotype. In conclusion, a reduced concentration of BH4 is not sufficient to alter ongoing pain sensitivity or evoked pain responses.
AB - Human studies have demonstrated a correlation between noncoding polymorphisms of "the pain protective" haplotype in the GCH1 gene that encodes for GTP cyclohydrolase I (GTPCH1)-which leads to reduced tetrahydrobiopterin (BH4) production in cell systems-and a diminished perception of experimental and clinical pain. Here, we investigate whether heterozygous mutations in the GCH1 gene which lead to a profound BH4 reduction in patients with dopa-responsive dystonia (DRD) have any effect on pain sensitivity. The study includes an investigation of GCH1-associated biomarkers and pain sensitivity in a cohort of 22 patients with DRD and 36 controls. The patients with DRD had, when compared with controls, significantly reduced levels of BH4, neopterin, biopterin, and GTPCH1 in their urine, blood, or cytokine-stimulated fibroblasts, but their pain response with respect to non-painful stimulation, (acute) stimulus-evoked pain, or pain response after capsaicin-induced sensitization was not significantly different. A family-specific cohort of 11 patients with DRD and 11 controls were included in this study. The patients with DRD were heterozygous for the pain protective haplotype in cis with the GCH1 disease-causing mutation, c.899T.C. No effect on pain perception was observed for this combined haplotype. In conclusion, a reduced concentration of BH4 is not sufficient to alter ongoing pain sensitivity or evoked pain responses.
KW - Capsaicin
KW - DOPA-responsive dystonia
KW - GCH1
KW - GTP cyclohydrolase 1
KW - GTPCH
KW - Pain
KW - Tetrahydrobiopterin
U2 - 10.1097/j.pain.0000000000001175
DO - 10.1097/j.pain.0000000000001175
M3 - Journal article
C2 - 29470312
AN - SCOPUS:85051720851
SN - 0304-3959
VL - 159
SP - 1012
EP - 1024
JO - Pain
JF - Pain
IS - 6
ER -
