TY - JOUR

T1 - Studies of variations of the cyclin-dependent kinase inhibitor 1C and the cyclin-dependent kinase 4 genes in relation to type 2 diabetes mellitus and related quantitative traits

AU - Nielsen, Eva-Maria D

AU - Hansen, Lars

AU - Stissing, Trine

AU - Yanagisawa, Keiko

AU - Borch-Johnsen, Knut

AU - Poulsen, Pernille

AU - Vaag, Allan

AU - Hansen, Torben

AU - Pedersen, Oluf

PY - 2005

Y1 - 2005

N2 - CDK4 is involved in the regulation of body weight, pancreatic beta-cell proliferation, insulin responsiveness, and diabetes pathogenesis. CDK4 activity is inhibited by CDKN1C, which is regulated by insulin. In addition, CDKN1C plays an important role in beta-cell proliferation and is involved in the pathogenesis of the Beckwith-Wiedemann syndrome, a disorder characterized by neonatal hyperinsulinaemic hypoglycaemia and pre- and post-natal overgrowth. The aim of this study was to investigate if variations in the proximal promoter and the coding region of the CDKN1C and CDK4 genes are associated with type 2 diabetes or changes in related quantitative phenotypes among glucose-tolerant subjects. Mutation analyses of the two genes in 62 type 2 diabetic patients resulted in the discovery of seven variants of CDKN1C and two variants of CDK4. In a case-control study comprising 717 type 2 diabetic patients and 518 glucose-tolerant subjects the most frequent variants did not show any difference in allele frequencies between the type 2 diabetic patients and the control subjects. However, in two genotype-quantitative trait correlation studies involving 206 glucose-tolerant offspring of type 2 diabetic patients and 359 young, healthy subjects the CDKN1C del171APVA variant associated with increased birth weight (P=0.05 and P=0.05). Furthermore, the same variant tended to be associated with decreased basal glucose oxidation among 16 genotypically discordant dizygotic twins (P=0.03). In a genotype-quantitative trait study involving 500 middle-aged glucose-tolerant subjects the CDK4 IVS2-31G-->A variant was associated with an increased waist circumference (P=0.03) and waist-to-hip ratio (P=0.02) and altered fasting plasma glucose (P=0.03). However, these later findings could not be replicated in additional studies. In conclusion, variants in CDKN1C may contribute to the inter-individual variation in birth weight.

AB - CDK4 is involved in the regulation of body weight, pancreatic beta-cell proliferation, insulin responsiveness, and diabetes pathogenesis. CDK4 activity is inhibited by CDKN1C, which is regulated by insulin. In addition, CDKN1C plays an important role in beta-cell proliferation and is involved in the pathogenesis of the Beckwith-Wiedemann syndrome, a disorder characterized by neonatal hyperinsulinaemic hypoglycaemia and pre- and post-natal overgrowth. The aim of this study was to investigate if variations in the proximal promoter and the coding region of the CDKN1C and CDK4 genes are associated with type 2 diabetes or changes in related quantitative phenotypes among glucose-tolerant subjects. Mutation analyses of the two genes in 62 type 2 diabetic patients resulted in the discovery of seven variants of CDKN1C and two variants of CDK4. In a case-control study comprising 717 type 2 diabetic patients and 518 glucose-tolerant subjects the most frequent variants did not show any difference in allele frequencies between the type 2 diabetic patients and the control subjects. However, in two genotype-quantitative trait correlation studies involving 206 glucose-tolerant offspring of type 2 diabetic patients and 359 young, healthy subjects the CDKN1C del171APVA variant associated with increased birth weight (P=0.05 and P=0.05). Furthermore, the same variant tended to be associated with decreased basal glucose oxidation among 16 genotypically discordant dizygotic twins (P=0.03). In a genotype-quantitative trait study involving 500 middle-aged glucose-tolerant subjects the CDK4 IVS2-31G-->A variant was associated with an increased waist circumference (P=0.03) and waist-to-hip ratio (P=0.02) and altered fasting plasma glucose (P=0.03). However, these later findings could not be replicated in additional studies. In conclusion, variants in CDKN1C may contribute to the inter-individual variation in birth weight.

KW - Aged

KW - Birth Weight

KW - Case-Control Studies

KW - Cyclin-Dependent Kinase 4

KW - Cyclin-Dependent Kinase Inhibitor p57

KW - Cyclin-Dependent Kinases

KW - DNA Mutational Analysis

KW - Denmark

KW - Diabetes Mellitus, Type 2

KW - Female

KW - Genetic Variation

KW - Glucose Tolerance Test

KW - Humans

KW - Insulin

KW - Male

KW - Middle Aged

KW - Nuclear Proteins

KW - Polymorphism, Genetic

KW - Promoter Regions, Genetic

KW - Proto-Oncogene Proteins

KW - Quantitative Trait, Heritable

KW - RNA, Messenger

U2 - 10.1007/s00109-005-0647-3

DO - 10.1007/s00109-005-0647-3

M3 - Journal article

C2 - 15821902

VL - 83

SP - 353

EP - 361

JO - Journal of Molecular Medicine

JF - Journal of Molecular Medicine

SN - 0946-2716

IS - 5

ER -