Poster Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2014


Victoria L Rudland 1 2 , Glynis P Ross 1 2 , Marcus Hinchcliffe 1 3 , Jason Pinner 3 , Stuart Cole 3 , Belinda Mercorella 3 , Lynda Molyneaux 2 , Maria Constantino 2 , Dennis K Yue 1 2 , Jencia Wong 1 2
  1. Discipline of Medicine, The University of Sydney, Sydney, NSW, Australia
  2. Diabetes Centre, Royal Prince Alfred Hospital, Sydney, NSW, Australia
  3. Department of Molecular and Clinical Genetics, Royal Prince Alfred Hospital, Sydney, NSW, Australia

Identification of glucokinase monogenic diabetes (GCK-MODY) in pregnancy is important as management differs substantially to gestational diabetes (GDM).  Screening criteria for GCK testing exist for non-pregnant populations(Fasting BGL 5.5-8mmol/L and increment <4.6mmol/L).  New pregnancy-specific GCK screening criteria have recently been proposed(Fasting BGL ≥5.5mmol/L and BMI <25kg/m2)1.  These criteria were developed in a predominantly Caucasian population.  Their widespread applicability to other ethnicities has not been investigated.  We examined the prevalence of GCK mutations in a multiethnic GDM cohort of 776 women attending the RPAH GDM clinic(2008-2012).  We identified 63/776 whose postnatal OGTT met standard GCK screening criteria, warranting genetic testing.  GCK mutations were detected by sequencing and multiplex ligation-dependent probe amplification.  For GCK-MODY cases found, we examined the performance of pregnancy-specific and standard criteria in pregnancy.  In a larger, multiethnic GDM cohort of 4115 women, we determined how many women would be identified for genetic testing using these criteria, stratified by ethnicity.  

31/63 women were available for genetic testing.  4 were diagnosed with GCK-MODY(Table 1), giving an estimated prevalence in GDM of 1.04%.  All Caucasian women would have been identified by the pregnancy-specific screening criteria.  However, one Indian subject would have been missed.  All would have been captured by the standard criteria applied in pregnancy.  In the larger GDM cohort, 6.1% vs 14.2% would be referred for genetic testing using the new and standard criteria, respectively; 3.2% Anglo-Celtic vs 8.0% SE Asian women would be referred with new criteria(Table 2).   

The estimated prevalence of GCK-MODY in our multiethnic GDM population is consistent with other studies. The new pregnancy-specific vs standard criteria will reduce the need for genetic testing by more than 50%, but refer a disproportionate number of Asian/Indian women.  The new criteria perform less well in these ethnicities vs Anglo-Celtic populations.  Ethnic-specific GCK screening criteria in pregnancy should be explored. 


  1. Chakera AJ, Spyer G, Vincent N, Ellard S, Hattersley AT, Dunne FP (2014) The 0.1% of the population with glucokinase monogenic diabetes can be recognized by clinical characteristics in pregnancy: the Atlantic Diabetes in Pregnancy cohort. Diabetes Care 37:1230-1236. doi:10.2337/dc13-2248.