Royal Blackburn Hospital, Blackburn, UK.
Introduction: Although type 1 diabetes is the most common type of diabetes in children, with the steady increase in type 2 and rare forms of diabetes, it may be sometimes difficult to ascertain the type of diabetes at the time of presentation. Some children present with a combination of features and do not fit into one of the classical types of diabetes. The rapid progress in the molecular genetics has helped to identify the specific diagnosis for these rare forms of diabetes. With the advent of newer techniques, the term undefined diabetes is becoming obsolete as a definitive diagnosis may be possible in majority of the cases.
Case series: We report a cohort of children in our clinic, who were initially classified as undefined type of diabetes. However over the years, majority of these children have received a definitive diagnosis which has helped appropriate treatment and counselling. In the cohort of 17 children (11% of clinic), we have confirmed 3 congenital generalised lipodystrophy (AGPAT-2 mutation), 2 Rogers syndrome, 2 DIDMOAD syndrome, 2 siblings one with Cohens syndrome and the other with insulin resistance, 1 Werners syndrome, 1 MODY and 1 Prader Willi syndrome with diabetes. The mean duration for reaching a definite diagnosis is 3 years. We still have 5 children with undefined type of diabetes who are being evaluated for a definitive diagnosis.
Conclusion: A detailed family history along with the evaluation of other associated features will aid the diagnosis. 35% of our cohort has severe visual involvement and it may be useful to consider routine visual screening in children with diabetes who are from a consanguineous background. It is essential to reach a definitive diagnosis, as this has implication for the siblings and the other family members. It also helps to estimate prognosis and plan for appropriate management.