Response to sirolimus in a case of diffuse congenital hyperinsulinaemic hypoglycaemia due to homozygous KCNJ11 mutation.

We present a case of a male neonate with refractory and persistent neonatal hypoglycaemia not responding to octreotide. On evaluation for hypoglycaemia, his cortisol was within the reference range while the serum insulin concentrations were high. Gallium-68 dotatate scan (GA-68 DOTA) showed diffuse pancreatic involvement. Genetic diagnosis of congenital hyperinsulinaemic hypoglycaemia due to KCNJ11 mutation was made. He was started on tablet sirolimus, after which the child was off all other medication and was euglycaemic. However, he developed bilateral pneumonia leading to acute respiratory distress syndrome with refractory shock. Our case highlights the response to sirolimus in a case of congenital hyperinsulinaemia (CHI) due to KCNJ11 mutation and severe adverse event thereafter.