Aims: To ascertain the incidence and aetiology of neonatal diabetes

Method: Active surveillance throughout the UK over 12 months

Results: Incidence 1;400,000 births. Total cases for analysis n=14 (11 TNDM, 2 PNDM, 1 died aged 3 days). >70% cases had severe IUGR.> 50% carried at least one type 1 diabetes resistant DQB1 allele. Islet cell antibodies were absent in PNDM and TNDM cases. In the patient that died, there was no evidence of insulitis. Insulin production in the neonatal period was negligible in all cases. TNDM predisposes to type 2 diabetes in later life(3 cases have now developed NIDDM). Three cases have paternal uniparental isodicomy of chromosome 6 while a further case has an unbalanced duplication of 6q 22-23 also carried by father and paternal grandmother neither of whom had TNDM or now have type 2 diabetes.

Conclusion: TNDM does not have an autoimmune aetiology. It predisposes to type 2 diabetes in later life. It is due to over expression of an imprinted gene in the region 6q 22-23.