Background: POU1F1 encodes a pituitary-specific homeodomain transcription factor that is crucial for development and differentiation of anterior pituitary cell types. Mutations in this gene result in GH, TSH and prolactin (PRL) deficiencies.
Objective and hypotheses: To describe a male newborn of a mother with known dominant p.R271W mutation in the POU1F1 gene.
Methods: Case report with clinical follow up, endocrine investigations, neuroimaging, and genetic analysis.
Results: Cord blood analysis suggested central hypothyroidism (TSH: 0.695 mU/l; fT4: 9 pmol/l), GH deficiency (0.06 nmol/l), and PRL deficiency (2 μmol/l). GH deficiency (0.07 μg/l) was confirmed during symptomatic hypoglycaemia (1.7 mmol/l) at day 2 of life. IGF1 (<32 μg/l) and IGFBP-3 (<0.5 mg/l) where low. MRI revealed a hypoplastic adenohypophysis (height: 1.7 mm). The knee-bone maturation was delayed. Thyroid hormone substitution was initiated at day 2 of life. Early GH treatment starting at 4 days of life (0.025 mg/kg per day) prevented further hypoglycaemias as controlled by continuous glucose monitoring. At the age of 2.5 months (minipuberty) the patient had normal activation of the gonadotropic axis (LH (2.7 UI/l), FSH (1 UI/l), testosterone (7.2 nmol/l), AMH (>210 ng/ml), Inhibine B (790 pg/ml)). Genetic analysis confirmed the p.R271W mutation in the POU1F1 gene.
Conclusion: The known maternal mutation enabled prompt screening of the newborn. Endocrine testing diagnosed central TSH, GH and PRL deficiencies and allowed early treatment. Genetic testing confirmed the presence of the same mutation as his mother. Early GH substitution prevented repeated hypoglycaemic events and eventual related complications. Long-term follow-up is needed to confirm normal growth and development.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology