A 33-year-old woman with Down syndrome was referred to our department for the investigation of low blood pressure. She was born, at term, to nonconsanguineous parents with no history of birth trauma, neonatal hypoglycemia, and prolonged jaundice. Her past medical history was unremarkable apart from surgery for tympanic imperforation. Her age at menarche was 12 years and she had regular periods. Her family history was notable for type 2 diabetes mellitus and arterial hypertension without any history of autoimmune diseases or congenital hypopituitarism.
The patient complained of asthenia, dizziness, and palpitation with arterial hypotension for the past 4 years. Concomitant capillary glucose levels were about 0.82 and 0.85 g/L. Neither bodyweight loss nor polyuria were reported. She was not taking any drugs.
On physical examination, she had a bodyweight of 64 kg, a height of 153 cm corresponding to a body mass index of 27.3 kg/m2, a blood pressure of 90/60 mmHg, and a regular pulse of 75 bpm. The skin was pale without hyperpigmentation. The hydration state and thyroid, abdominal, and neurological examinations were normal.
The results of biological investigations are shown in Table 1. The thyroid function was normal and anti-thyroperoxidase antibodies were negative. The peak of the cortisol level in response to the insulin-induced hypoglycemia test was 9.4 mug/dl. The ACTH level was normal indicating corticotrope deficiency. Other pituitary hormones were normal, consisting with the diagnosis of an isolated corticotrope deficiency.
Magnetic resonance imaging (MRI) scan revealed a small and homogeneous anterior pituitary gland with a partially empty sella turcica. There was no tumor and the posterior lobe bright spot was normal. The pituitary stalk was median and thin (Figure 1).
Genetic analysis using high-throughput sequencing showed no mutations and no copy number variants of the TBX19 and NFKB2 genes. Pituitary antibodies were not available.
Lifelong replacement therapy with an oral hydrocortisone dose of 20 mg per day was prescribed to our patient. The other pituitary hormones remained normal over the course of follow-up.