ESPE Abstracts

Background: Human HSD11B2 metabolizes active cortisol into cortisone and protects the mineralocorticoid receptor from glucocorticoid occupancy. Loss of function mutations in HSD11B2 gene cause a rare autosomal recessive disorder, apparent mineralocorticoid excess, resulting in low-renin hypertension and hypokalemia.

Objective: We present 2 children with apparent mineralocorticoid excess. Case 1, a boy presenting at 11 years with growth retardation (SD, −2.8), polyuria, polydipsia, hypertension (160/110–170/140 mm Hg). Biochemical analysis showed hypokalemia (2.2–2.7 mmol/l) with normal sodium (140–142 mmol/l). Plasma renin activity and serum aldosterone were undetectable (PRA 0.14 ng/ml per h, SA <30.0 pmol/l). Case 2, a girl presenting at the age of 6 years with polyuria, high blood pressure (120/85–130/90 mm Hg) and hypokalemia (2.4 mmol/l). Hormonal study also showed low levels of PRA (<0.1 ng/ml per h) and SA (32.3 pmol/l). Therapy with spironolactone (50 mg per day) was started. At present the children show normal electrolytes and PRA, and blood pressure 100/70–110/80 mm Hg.

Methods: HSD11B2 gene was analysed by Sanger sequencing.

Results: Compound heterozygous p.G341S/p.H304R and a homozygous p.M243V mutations were found in Case 1 and Case 2, respectively. All mutations were novel.

Conclusion: In the present study we described clinical and molecular genetic characterization of two patients with novel mutations in HSD11B2 gene.