Restoration of Height after 11 Years of Letrozole Treatment in 11β-Hydroxylase Deficiency

11β-hydroxylase deficiency (11β-OHD) is the second most common form of congenital adrenal hyperplasia (CAH). Males with 11β-OHD CAH are often diagnosed late with a significantly advanced bone age leading to a poor height prognosis due to early closure of epiphysis. Delaying epiphyseal fusion by treatment of aromatase inhibitors (AIs) might be a useful strategy in patients with very advanced bone ages. However, there are limited data regarding the effect on final height and long-term safety of this approach. We report our experience with 11 years of letrozole treatment and 17 years of follow-up in a boy with 11β-OHD. He presented at 2 years and 11 months of age with a bone age of 13 years (predicted adult height, PAH, 129.5 cm). Letrozole was added after 1 year of glucocorticoid treatment due to no improvement in height prognosis (130 cm), and continued until the age of 14 years and 11 months. He also received GnRH analog treatment at 10 years and 3 months of age for 2.5 years due to central activation of puberty. He reached a final height of 165.2 cm (35.2 cm above his PAH). This long-term treatment with letrozole was associated with changes in vertebral morphology such as vertebral body end-plate changes, Schmorl nodes, and mild protrusions in the intervertebral discs. Testicular volumes, gonadotropins, testosterone, and anti-Müllerian hormone were normal at age 20 years. A spermiogram showed a normal count but impaired sperm motility and morphology. This unique case represents the longest duration of AI treatment reported in CAH and the first case in which letrozole was started before puberty with the final height reported. We conclude that AIs may restore height in selected patients with CAH with very advanced bone age and severely compromised height prognosis.

Vanishing 17-Hydroxyprogesterone Concentrations in 21-Hydroxylase Deficiency

We present a boy with a genetically proven congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. While massively elevated 17-hydroxyprogesterone (17-OHP) concentrations after birth led to the diagnosis, 17-OHP concentrations became immeasurable starting with the second year of life even though the dose of hydrocortisone was continuously decreased to ∼7 mg/m2/day. Furthermore, 17-OHP levels were immeasurable during the ACTH test and after withdrawing hydrocortisone medication. In contrast, ACTH levels increased after cessation of hydrocortisone treatment suggesting complete primary adrenal cortex failure. We discuss this case based on the differential diagnosis of complete adrenal cortex failure including other genetic causes in addition to CAH, prednisolone treatment, autoimmune adrenalitis, adrenoleukodystrophy, CMV infection, and adrenal hemorrhage infarction. The most likely disease in our boy is autoimmune adrenalitis, which is difficult to prove years after the onset of the disease. Treatment of CAH had masked the classical symptoms of complete adrenal cortex insufficiency leading to delayed diagnosis in this case.