Diabetes mellitus is a common chronic disease in children. Type 1A and type 2 are the two major types of diabetes mellitus (T1DM and T2DM) which account for >95 per cent of cases of diabetes in children. T1DM results from immune-mediated destruction of pancreatic β-cells progressing to absolute insulin deficiency and constitutes the majority of cases of diabetes in children1. The incidence of T1DM varies widely with age-adjusted incidences ranging from low of 0.1/100,000 per year in China and Venezuela to as high as 40/100,000 per year in Sardinia and 60/100,000 in Finland1. The incidence of T1DM worldwide has been increasing by approximately 2-3 per cent per year for the past few decades. This increase is likely to be multifactorial in origin including higher rates of accurate and complete ascertainment of new cases. Unknown environmental causes must also play a role since genetic alterations in the population cannot explain such secular trends1. In India, there are approximately 90,000 children with T1DM2. However, these estimates are based on studies in the 1990s restricted to certain regions in India. The Indian Council of Medical Research, New Delhi, India, established the Registry of People with Diabetes with Young Age at Onset (YDR) in 20063. This is an observational, multicentre, clinic-based registry of physician-diagnosed diabetes in individuals below 25 yr of age. The major objectives of YDR are to generate information on the epidemiology of youthonset diabetes within India.