Cargando…
Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia
Heterozygous glucokinase (GCK) mutations cause a subtype of maturity-onset diabetes of the young (GCK-MODY). Over 600 GCK mutations have been reported of which ∼65% are missense. In many cases co-segregation has not been established and despite the importance of functional studies in ascribing patho...
Autores principales: | , , , , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2012
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321013/ https://www.ncbi.nlm.nih.gov/pubmed/22493702 http://dx.doi.org/10.1371/journal.pone.0034541 |
_version_ | 1782228901926273024 |
---|---|
author | Valentínová, Lucia Beer, Nicola L. Staník, Juraj Tribble, Nicholas D. van de Bunt, Martijn Hučková, Miroslava Barrett, Amy Klimeš, Iwar Gašperíková, Daniela Gloyn, Anna L. |
author_facet | Valentínová, Lucia Beer, Nicola L. Staník, Juraj Tribble, Nicholas D. van de Bunt, Martijn Hučková, Miroslava Barrett, Amy Klimeš, Iwar Gašperíková, Daniela Gloyn, Anna L. |
author_sort | Valentínová, Lucia |
collection | PubMed |
description | Heterozygous glucokinase (GCK) mutations cause a subtype of maturity-onset diabetes of the young (GCK-MODY). Over 600 GCK mutations have been reported of which ∼65% are missense. In many cases co-segregation has not been established and despite the importance of functional studies in ascribing pathogenicity for missense variants these have only been performed for <10% of mutations. The aim of this study was to determine the minimum prevalence of GCK-MODY amongst diabetic subjects in Slovakia by sequencing GCK in 100 Slovakian probands with a phenotype consistent with GCK-MODY and to explore the pathogenicity of identified variants through family and functional studies. Twenty-two mutations were identified in 36 families (17 missense) of which 7 (I110N, V200A, N204D, G258R, F419S, c.580-2A>C, c.1113–1114delGC) were novel. Parental DNA was available for 22 probands (covering 14/22 mutations) and co-segregation established in all cases. Bioinformatic analysis predicted all missense mutations to be damaging. Nine (I110N, V200A, N204D, G223S, G258R, F419S, V244G, L315H, I436N) mutations were functionally evaluated. Basic kinetic analysis explained pathogenicity for 7 mutants which showed reduced glucokinase activity with relative activity indices (RAI) between 0.6 to <0.001 compared to wild-type GCK (1.0). For the remaining 2 mutants additional molecular mechanisms were investigated. Differences in glucokinase regulatory protein (GKRP) –mediated-inhibition of GCK were observed for both L315H & I436N when compared to wild type (IC(50) 14.6±0.1 mM & 20.3±1.6 mM vs.13.3±0.1 mM respectively [p<0.03]). Protein instability as assessed by thermal lability studies demonstrated that both L315H and I436N show marked thermal instability compared to wild-type GCK (RAI at 55°C 8.8±0.8% & 3.1±0.4% vs. 42.5±3.9% respectively [p<0.001]). The minimum prevalence of GCK-MODY amongst Slovakian patients with diabetes was 0.03%. In conclusion, we have identified 22 GCK mutations in 36 Slovakian probands and demonstrate that combining family, bioinformatic and functional studies can aid the interpretation of variants identified by molecular diagnostic screening. |
format | Online Article Text |
id | pubmed-3321013 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-33210132012-04-10 Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia Valentínová, Lucia Beer, Nicola L. Staník, Juraj Tribble, Nicholas D. van de Bunt, Martijn Hučková, Miroslava Barrett, Amy Klimeš, Iwar Gašperíková, Daniela Gloyn, Anna L. PLoS One Research Article Heterozygous glucokinase (GCK) mutations cause a subtype of maturity-onset diabetes of the young (GCK-MODY). Over 600 GCK mutations have been reported of which ∼65% are missense. In many cases co-segregation has not been established and despite the importance of functional studies in ascribing pathogenicity for missense variants these have only been performed for <10% of mutations. The aim of this study was to determine the minimum prevalence of GCK-MODY amongst diabetic subjects in Slovakia by sequencing GCK in 100 Slovakian probands with a phenotype consistent with GCK-MODY and to explore the pathogenicity of identified variants through family and functional studies. Twenty-two mutations were identified in 36 families (17 missense) of which 7 (I110N, V200A, N204D, G258R, F419S, c.580-2A>C, c.1113–1114delGC) were novel. Parental DNA was available for 22 probands (covering 14/22 mutations) and co-segregation established in all cases. Bioinformatic analysis predicted all missense mutations to be damaging. Nine (I110N, V200A, N204D, G223S, G258R, F419S, V244G, L315H, I436N) mutations were functionally evaluated. Basic kinetic analysis explained pathogenicity for 7 mutants which showed reduced glucokinase activity with relative activity indices (RAI) between 0.6 to <0.001 compared to wild-type GCK (1.0). For the remaining 2 mutants additional molecular mechanisms were investigated. Differences in glucokinase regulatory protein (GKRP) –mediated-inhibition of GCK were observed for both L315H & I436N when compared to wild type (IC(50) 14.6±0.1 mM & 20.3±1.6 mM vs.13.3±0.1 mM respectively [p<0.03]). Protein instability as assessed by thermal lability studies demonstrated that both L315H and I436N show marked thermal instability compared to wild-type GCK (RAI at 55°C 8.8±0.8% & 3.1±0.4% vs. 42.5±3.9% respectively [p<0.001]). The minimum prevalence of GCK-MODY amongst Slovakian patients with diabetes was 0.03%. In conclusion, we have identified 22 GCK mutations in 36 Slovakian probands and demonstrate that combining family, bioinformatic and functional studies can aid the interpretation of variants identified by molecular diagnostic screening. Public Library of Science 2012-04-06 /pmc/articles/PMC3321013/ /pubmed/22493702 http://dx.doi.org/10.1371/journal.pone.0034541 Text en Valentínová et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Valentínová, Lucia Beer, Nicola L. Staník, Juraj Tribble, Nicholas D. van de Bunt, Martijn Hučková, Miroslava Barrett, Amy Klimeš, Iwar Gašperíková, Daniela Gloyn, Anna L. Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia |
title | Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia |
title_full | Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia |
title_fullStr | Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia |
title_full_unstemmed | Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia |
title_short | Identification and Functional Characterisation of Novel Glucokinase Mutations Causing Maturity-Onset Diabetes of the Young in Slovakia |
title_sort | identification and functional characterisation of novel glucokinase mutations causing maturity-onset diabetes of the young in slovakia |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321013/ https://www.ncbi.nlm.nih.gov/pubmed/22493702 http://dx.doi.org/10.1371/journal.pone.0034541 |
work_keys_str_mv | AT valentinovalucia identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT beernicolal identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT stanikjuraj identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT tribblenicholasd identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT vandebuntmartijn identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT huckovamiroslava identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT barrettamy identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT klimesiwar identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT gasperikovadaniela identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT gloynannal identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia |