The girl was aged 11.7 years at diagnosis; she had a severe height deficit (hSDS −3.13), a GH peak of 7.43 μg/L and a severe IGF-1 deficiency (IGF-1 SDS −2.11) that persisted at retesting (IGF-1 SDS −2.57). This evidence concerns the gene GH1 and hyperinsulinemic hypoglycemia, familial, 4.