ESPE Abstracts

Background: Dopamine beta-hydroxylase (DBH) deficiency is characterized by lack of sympathetic noradrenergic function. Affected individuals exhibit profound deficits in autonomic regulation of cardiovascular function. DBH deficiency is a congenital disorder; however, the diagnosis is not generally recognized until late childhood. In this report, we present a case with DBH deficiency leading to growth hormone deficiency.

Case: A ten year old girl who has been taking growth hormone therapy was referred with a history of sudden onset malaise and somnolence. Her body weight and height were 19 kg (−2.4 S.D) and 115 cm (−2.3 S.D.), respectively. Physical examination findings were unremarkable except for irregular heartbeat and blood pressure, somnolence, and weak deep tendon reflexes. Ophthalmoscopic eye and cardiovascular examinations were normal. Laboratory studies revealed abnormal levels of serum catecholamins and their urine metabolites. Serum epinephrine was measured as 11.1 pg/ml (N: 4–83), norepinephrine as 78.1 pg/ml (N: 80–498), dopamine as 52.9 pg/ml (<30), urine metanephrine as 47 μg/day (N: 26–230), and normetanephrine as 40.8 μg/day (N: 44–540). Other laboratory and radiological studies were unremarkable. Oral administration of 50 mg Droxidopa, twice daily, increased blood pressure and reversed all symptoms.

Conclusion: This patient with growth hormone deficiency is the first case associated with DBH deficiency. Norepinephrine is a major regulator of the release of growth hormone. Low norepinephrine synthesis inhibits growth hormone secretion. DBH deficiency should keep in mind in case of irregular heartbeat and blood pressure together with growth hormone deficiency.