The p.R63W mutation in the hepatocyte nuclear factor-4 alpha (HNF4A) results in macrosomia and atypical Fanconi syndrome, in addition to hyperinsulinaemic hypoglycaemia (HI).
The authors report a case of familial hyperinsulinemic hypoglycemia with homozygous T294M mutation of the KCNJ11 gene, which responded to diazoxide therapy.