Prevalence of monogenic diabetes amongst Polish children after a nationwide genetic screening campaign

Abstract

Aims/hypothesis: The aim of this study was to study dynamic changes in the prevalence of different types of diabetes in paediatric populations in Poland, with a specific focus on monogenic diabetes (MD).

Methods: Using epidemiologic data (PolPeDiab Collaboration) and nationwide genetic test results (TEAM Programme), we compared the prevalence of type 1, type 2 and cystic fibrosis-related diabetes (CFRD) and MD. Genetically confirmed MD included MODY, neonatal diabetes and Wolfram and Alström syndromes. The study covered all children aged 0-18 years treated for diabetes between 2005 and 2011 in three regions, inhabited by 23.7% (1,989,988) of Polish children, with a low prevalence of childhood obesity (<5%).

Results: The prevalence of type 1 diabetes showed a continuous increase, from 96 to 138/100,000 children. The prevalence of type 2 diabetes and CFRD also increased, from 0.3 to 1.01/100,000 children and from 0.1 to 0.95/100,000 children, respectively. The prevalence of MD was stable at between 4.2 and 4.6/100,000 children, accounting for 3.1-4.2% of children with diabetes, with glucokinase (GCK)-MODY being the most frequent type, amounting to 83% of patients with MD. The percentage of positive test results decreased with the number of referrals, suggesting that children with the highest probability of MD were referred initially, followed by those with a less clear-cut phenotype. The prevalence of neonatal diabetes equalled 1 in 300,000 children.

Conclusions/interpretation: The prevalence of MD in a paediatric population with a low prevalence of obesity remains stable and is nearly fivefold higher than that of type 2 diabetes and CFRD, justifying a need for increased access to genetic diagnostic procedures in diabetic children.

Fig. 1

(a) Increase of referral rate throughout the study period. The lower area (dark grey) represents patients with positive genetic test results for any kind of MD. The upper area (light grey) represents children referred for genetic testing and with negative genetic test results. GCK-MODY was the most commonly observed form, detected in 83% of children referred for genetic screening, followed by neonatal diabetes (7%), HNF1A/HNF4A-MODY (4%), HNF1B-MODY (2%) and diabetes in Wolfram and Alström syndromes (2% and 1%, respectively). (b) Number of children with type 1 diabetes (T1DM, circles), type 2 diabetes (T2DM, diamonds), monogenic diabetes (MD, squares) and CFRD (triangles) treated at the three study centres throughout the study region. Owing to the rapidly increasing number of children with type 1 diabetes, the percentage of diabetic patients with MD relative to the overall population of diabetic children decreased from 4.1% in 2005 to 3.2% in 2011, while the percentages of type 1 diabetes, type 2 diabetes and CFRD all increased. The left hand axis depicts the number of children with type 1 diabetes, while the right hand axis shows the number of children with monogenic or type 2 diabetes or CFRD