Conference abstract
Next Generation Sequencing identifies 1.9% of monogenic diabetes amongst children and young adults clinically diagnosed as having type 1 diabetes in Cameroon
Pan African Medical Journal - Conference Proceedings. 2023:17(78).04
Jun 2023.
doi: 10.11604/pamj-cp.2023.17.78.1845
Archived on: 04 Jun 2023
Contact the corresponding author
Keywords: Monogenic diabetes, young-onset diabetes, islet autoantibody, C-peptide, Cameroon
Oral presentation
Next Generation Sequencing identifies 1.9% of monogenic diabetes amongst children and young adults clinically diagnosed as having type 1 diabetes in Cameroon
Jean-Claude Katte1,2,&, Adele Bodieu Chetcha1, Mesmin Dehayem1, Andrew Hattersley2,3, Timothy McDonald2,4, Angus Jones2,3, Eugene Sobngwi1,6
1National Obesity Centre and Endocrinology and Metabolic Diseases Unit, Yaoundé Central Hospital, Yaoundé, Cameroon, 2Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom, 3Macleod Diabetes and Endocrine Centre, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom, 4Academic Department of Clinical Biochemistry, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom, 5Department of Internal Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
&Corresponding author
Introduction: monogenic diabetes is a rare form of diabetes common in children and young adults and can easily be mistaken for type 1 diabetes. Islet autoantibodies and C-peptide testing has been shown to robustly exclude people with type 1 diabetes allowing targeted genetic testing on those who are mostly likely to have monogenic diabetes. We aimed to establish the prevalence of monogenic diabetes amongst children and young adults with diabetes using a targeted approach based on biomarker screening and genetic testing.
Methods: we studied 259 children and young adults with insulin-treated diabetes diagnosed at an age < 30 years attending type 1 diabetes clinics in Yaoundé and Bafoussam, in Cameroon. Triple islet autoantibodies (GAD, IA2, ZnT8) were measured in serum using an ELISA technique. Islet autoantibody negative participants were selected for C-peptide analysis. C-peptide was measured in plasma by direct electrochemiluminescence immunoassay technique. C-peptide-positive participants (C-peptide >200 pmol/L) were then selected for genetic testing for all 29 identified causes of monogenic diabetes.
Results: a total of 1.9% of the participants (5 of 259 participants) had monogenic diabetes (1 HNF1A, HNF1B, 1 INSR, 1 Mt: 3243, 1 HNF4A). All participants were started on insulin at the time of diabetes diagnosis. Three (3) of five (5) participants did not have an affected parent with diabetes. The 2 participants with an affected parent had the Mt: 3243 mutation (Mother) and HNF4A mutation (Mother). The median (IQR) T1DGRS was significantly lower in the participants with monogenic diabetes compared to those with autoimmune type 1 diabetes: 7.94 (7.91 - 10.29) vs 11.61 (9.93 - 12.83), p<0.001.
Conclusion: this is one of the first studies in sub-Saharan Africa to confirm the prevalence of 1.9% of people with monogenic diabetes amongst individuals with young-onset diabetes diagnosed at an age < 30 years in Cameroon.
Next Generation Sequencing identifies 1.9% of monogenic diabetes amongst children and young adults clinically diagnosed as having type 1 diabetes in Cameroon
Jean-Claude Katte1,2,&, Adele Bodieu Chetcha1, Mesmin Dehayem1, Andrew Hattersley2,3, Timothy McDonald2,4, Angus Jones2,3, Eugene Sobngwi1,6
1National Obesity Centre and Endocrinology and Metabolic Diseases Unit, Yaoundé Central Hospital, Yaoundé, Cameroon, 2Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom, 3Macleod Diabetes and Endocrine Centre, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom, 4Academic Department of Clinical Biochemistry, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom, 5Department of Internal Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
&Corresponding author
Introduction: monogenic diabetes is a rare form of diabetes common in children and young adults and can easily be mistaken for type 1 diabetes. Islet autoantibodies and C-peptide testing has been shown to robustly exclude people with type 1 diabetes allowing targeted genetic testing on those who are mostly likely to have monogenic diabetes. We aimed to establish the prevalence of monogenic diabetes amongst children and young adults with diabetes using a targeted approach based on biomarker screening and genetic testing.
Methods: we studied 259 children and young adults with insulin-treated diabetes diagnosed at an age < 30 years attending type 1 diabetes clinics in Yaoundé and Bafoussam, in Cameroon. Triple islet autoantibodies (GAD, IA2, ZnT8) were measured in serum using an ELISA technique. Islet autoantibody negative participants were selected for C-peptide analysis. C-peptide was measured in plasma by direct electrochemiluminescence immunoassay technique. C-peptide-positive participants (C-peptide >200 pmol/L) were then selected for genetic testing for all 29 identified causes of monogenic diabetes.
Results: a total of 1.9% of the participants (5 of 259 participants) had monogenic diabetes (1 HNF1A, HNF1B, 1 INSR, 1 Mt: 3243, 1 HNF4A). All participants were started on insulin at the time of diabetes diagnosis. Three (3) of five (5) participants did not have an affected parent with diabetes. The 2 participants with an affected parent had the Mt: 3243 mutation (Mother) and HNF4A mutation (Mother). The median (IQR) T1DGRS was significantly lower in the participants with monogenic diabetes compared to those with autoimmune type 1 diabetes: 7.94 (7.91 - 10.29) vs 11.61 (9.93 - 12.83), p<0.001.
Conclusion: this is one of the first studies in sub-Saharan Africa to confirm the prevalence of 1.9% of people with monogenic diabetes amongst individuals with young-onset diabetes diagnosed at an age < 30 years in Cameroon.
