Baseline pituitary investigation showed increased levels of IGF1 (587.5 ng/mL, NR 74–450), random GH 11.3 ng/mL (NR 0.12–8.1), hyperprolactinaemia with PRL 35.1 ng/mL (NR 4.4–19), central hypothyroidism with TSH 2.3 μUI/mL (NR 0.51–4.30) and FT4 6.96 pmol/L (NR 12.6–21), morning cortisol of 10.3 μg/dL (NR 6.2–12.5), total testosterone 238 ng/dL (NR 105–545), FSH 3.49 U/L (NR 1.5–8.6), LH 1.64 U/L (NR 1.7–8.6). The gene discussed is GH1; the disease is Increased circulating prolactin concentration.