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...
Main Authors: | , , , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Public Library of Science (PLoS)
2012-01-01
|
Series: | PLoS ONE |
Online Access: | http://europepmc.org/articles/PMC3321013?pdf=render |
id |
doaj-dcb84374485d4c3eb7c33ea7ba2112e7 |
---|---|
record_format |
Article |
spelling |
doaj-dcb84374485d4c3eb7c33ea7ba2112e72020-11-24T21:52:12ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0174e3454110.1371/journal.pone.0034541Identification and functional characterisation of novel glucokinase mutations causing maturity-onset diabetes of the young in Slovakia.Lucia ValentínováNicola L BeerJuraj StaníkNicholas D TribbleMartijn van de BuntMiroslava HučkováAmy BarrettIwar KlimešDaniela GašperíkováAnna L GloynHeterozygous 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.http://europepmc.org/articles/PMC3321013?pdf=render |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Lucia Valentínová Nicola L Beer Juraj Staník Nicholas D Tribble Martijn van de Bunt Miroslava Hučková Amy Barrett Iwar Klimeš Daniela Gašperíková Anna L Gloyn |
spellingShingle |
Lucia Valentínová Nicola L Beer Juraj Staník Nicholas D Tribble Martijn van de Bunt Miroslava Hučková Amy Barrett Iwar Klimeš Daniela Gašperíková Anna L Gloyn Identification and functional characterisation of novel glucokinase mutations causing maturity-onset diabetes of the young in Slovakia. PLoS ONE |
author_facet |
Lucia Valentínová Nicola L Beer Juraj Staník Nicholas D Tribble Martijn van de Bunt Miroslava Hučková Amy Barrett Iwar Klimeš Daniela Gašperíková Anna L Gloyn |
author_sort |
Lucia Valentínová |
title |
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_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_sort |
identification and functional characterisation of novel glucokinase mutations causing maturity-onset diabetes of the young in slovakia. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS ONE |
issn |
1932-6203 |
publishDate |
2012-01-01 |
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. |
url |
http://europepmc.org/articles/PMC3321013?pdf=render |
work_keys_str_mv |
AT luciavalentinova identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT nicolalbeer identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT jurajstanik identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT nicholasdtribble identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT martijnvandebunt identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT miroslavahuckova identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT amybarrett identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT iwarklimes identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT danielagasperikova identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia AT annalgloyn identificationandfunctionalcharacterisationofnovelglucokinasemutationscausingmaturityonsetdiabetesoftheyounginslovakia |
_version_ |
1725876214357295104 |