Emergence of insulin resistance following empirical glibenclamide therapy: a case report of neonatal diabetes with a recessive INS gene mutation.

BACKGROUND

As KATP channel mutations are the most common cause of neonatal diabetes mellitus (NDM) and patients with these mutations can be treated with oral sulfonylureas, empiric therapy is a common practice for NDM patients.

CASE PRESENTATION: A non-syndromic, small for gestational age baby born to first-degree consanguineous parents was diagnosed with NDM. Because of hypo- and hyperglycemic episodes and variability in insulin requirement, we initiated a trial of glibenclamide, with a presumptive diagnosis of NDM caused by a KATP channel mutation. However, this empiric sulfonylurea trial did not improve the patient's glycemic control and resulted in resistance to exogenous insulin. Genetic testing identified a previously reported homozygous INS promoter mutation (c.-331C>G), which was not responsive to sulfonylurea therapy.

CONCLUSIONS

In light of our results, we recommend to confirm the genetic diagnosis as soon as possible and decide on sulfonylurea treatment after a genetic diagnosis is confirmed.