title: Genetic and clinical characteristics of maturity-onset diabetes of the young in Chinese patients.
abstract: In Caucasians, maturity-onset diabetes of the young (MODY) is mostly caused by mutations in the hepatocyte nuclear factor (HNF)-1alpha (MODY3) and glucokinase (MODY2) genes. Most Japanese MODY patients, however, are not linked to known MODY genes. In this study, we examined the genetic and clinical characteristics of Chinese subjects with MODY. The study included 146 unrelated families fulfilling the minimum criteria for MODY: two consecutive generations of type II diabetes with at least one member diagnosed under the age of 25. We screened for mutations in the HNF-4alpha (MODY1), MODY2 and MODY3 genes by direct sequencing. Antibody to glutamic acid decarboxylase (GAD-Ab) was measured in subjects with MODY of unknown cause (MODYX). Insulin resistance index and other clinical data were compared in sex-, age- and duration-matched MODY3 and MODYX patients. In all, 13 families had MODY3 mutations and two had MODY2 mutations. No MODY1 mutation was found. Four of the 12 different MODY3 mutations were newly identified novel mutations (Q243E, A311D, P379R and P488fsdelC). In subjects with MODYX, 3% were GAD-Ab positive and 60% were overweight. Compared to MODY3 patients, MODYX patients had higher body mass index (P<0.02), higher insulin resistance index (P=0.001) and triglyceride level (P<0.02), lower HDL level (P=0.001) and more hypertension (P<0.05), but no significant difference in the prevalence of diabetic complications. In conclusion, MODY3 and MODY2 account for only 9 and 1%, respectively, of Chinese MODY. A majority of Chinese MODY patients are due to defects in unknown genes and appear to be characterized by insulin resistance.
authors.affiliation: Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong, China.
authors.forename: Jian Yu
authors.initials: JY
authors.lastname: Xu
authors.forename: Qing Hong
authors.initials: QH
authors.lastname: Dan
authors.forename: Vivian
authors.initials: V
authors.lastname: Chan
authors.forename: Nelson M S
authors.initials: NM
authors.lastname: Wat
authors.forename: Sidney
authors.initials: S
authors.lastname: Tam
authors.forename: Sau Cheung
authors.initials: SC
authors.lastname: Tiu
authors.forename: Ka Fai
authors.initials: KF
authors.lastname: Lee
authors.forename: Shing Chung
authors.initials: SC
authors.lastname: Siu
authors.forename: Man Wo
authors.initials: MW
authors.lastname: Tsang
authors.forename: Lai Ming
authors.initials: LM
authors.lastname: Fung
authors.forename: Kin Wah
authors.initials: KW
authors.lastname: Chan
authors.forename: Karen S L
authors.initials: KS
authors.lastname: Lam
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004268:DNA-Binding Proteins / Q000235:genetics*; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D005820:Genetic Testing; D005941:Glucokinase / Q000235:genetics*; D005968:Glutamate Decarboxylase / Q000276:immunology / Q000378:metabolism; D051537:Hepatocyte Nuclear Factor 1; D051538:Hepatocyte Nuclear Factor 1-alpha; D051557:Hepatocyte Nuclear Factor 4; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree; D010750:Phosphoproteins / Q000235:genetics*; D011965:Receptors, Glucocorticoid / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; C496487:HNF1A protein, human; C496592:HNF4A protein, human; D051538:Hepatocyte Nuclear Factor 1-alpha; D051557:Hepatocyte Nuclear Factor 4; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011965:Receptors, Glucocorticoid; D014157:Transcription Factors; D051537:Hepatocyte Nuclear Factor 1; D005941:Glucokinase; D005968:Glutamate Decarboxylase