title: GCK monogenic diabetes and gestational diabetes: possible diagnosis on clinical grounds.
abstract: OBJECTIVE
  To determine if the previously published clinical criteria for identifying glucokinase monogenic diabetes [GCK gene mutation in maturity-onset diabetes of the young (GCK-MODY)], an elevated antenatal fasting blood glucose of 5.5-8.0 mmol/l, an increment of < 4.6 mmol/l at 2 h in an oral glucose tolerance test and slim are applicable in a large multi-ethnic cohort of women with gestational diabetes.
  
  
  METHODS
  We analysed de-identified data from all women with gestational diabetes, diagnosed using the Australasian Diabetes in Pregnancy Society (1998) Australian criteria at our institution between 1993 and 2013, making comparisons among those with complete antenatal data including: diagnostic oral glucose tolerance test results meeting the above criteria; pregestational BMI; birth outcomes; and postpartum oral glucose tolerance test data. We categorized these women into two groups: Group A1 had a BMI ≤ 21 kg/m(2) and Group A2 had a BMI > 21 kg/m(2) and < 25 kg/m(2).
  
  
  RESULTS
  Of the 302 women meeting the study entry criteria, we had complete data including a postpartum oral glucose tolerance test result for 171 women: 54 in Group A1 and 117 in Group A2. Ethnicity was significantly different between the groups. The oral glucose tolerance test and postpartum HbA1c results identified few women ( < 14%) in Group A1 and Group A2 who still had 'possible GCK-MODY'.
  
  
  CONCLUSIONS
  Our findings indicate that previously recommended clinical criteria for the identification of women likely to have GCK-MODY lack specificity in a cohort of women with multi-ethnic backgrounds. Using these criteria to select women for testing for GCK-MODY in pregnancy would therefore be costly and is likely to yield few women positive for this condition.
authors.affiliation: Department of Diabetes and Endocrinology, Bankstown-Lidcombe Hospital, Bankstown, NSW, Australia.|Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
authors.forename: J R
authors.initials: JR
authors.lastname: Flack
authors.affiliation: Department of Diabetes and Endocrinology, Bankstown-Lidcombe Hospital, Bankstown, NSW, Australia.|Faculty of Medicine, University of Sydney, Sydney, NSW, Australia.
authors.forename: G P
authors.initials: GP
authors.lastname: Ross
authors.affiliation: Faculty of Medicine, University of Sydney, Sydney, NSW, Australia.|Department of Diabetes and Endocrinology, Westmead Hospital, Westmead, NSW, Australia.
authors.forename: N W
authors.initials: NW
authors.lastname: Cheung
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics; D016640:Diabetes, Gestational / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics; D003937:Diagnosis, Differential; D057286:Electronic Health Records; D005260:Female; D005500:Follow-Up Studies; D005941:Glucokinase / Q000235:genetics* / Q000378:metabolism; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D009154:Mutation; D009517:New South Wales; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics; D011296:Prenatal Diagnosis; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose; D005941:Glucokinase; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human