My daughter, diagnosed with type 1 diabetes five months ago, had a 13% hemoglobin A1c at the time of diagnosis. She is twice daily NPH, and her recent A1c tests have been (respectively) 7.5% and now 6.4%. All antibody tests for type 1 and MODY2 are negative. Is this possibly something other than type 1 in a honeymoon period?

With an onset that was acutely insulin dependent and with negative antibody tests, the most likely diagnosis is type 1B (idiopathic) diabetes. This is characterised by an onset that is very similar to that of the much more common autoimmune form of type 1A (autoimmune) diabetes, and it is quite uncommon, occurring in about 5% in new onset Caucasian families but constitutes a little over 50% of African American and Hispanic cases. Characteristically, these children are antibody negative. The pathology is not yet understood in molecular terms, but there does seem to be an underlying insulin deficiency. Although as many as half may be able to control their blood sugars on oral hypoglycemic agents or even by just exercise and diet for sometime in the first year, the expectation is that they will at some stage become insulin dependent again.

Besides MODY2, there are other possibilities of which MODY 3 is the most common one that might present this way. Aside from genetic counselling and the possible use of sulfonylureas in MODY 3, I am not convinced however that a specific diagnosis is really necessary because what is important is the long term control of blood sugars to as near normal as possible and by the simplest means.

DOB