CONGENITAL adrenal hyperplasia due to 21-hydroxylase deficiency is a relatively common genetic disorder. On the basis of worldwide screening programs, the incidence has been calculated to be approximately 1 per 14,000 births.1 Despite impressive advances in treatment and in our understanding of the molecular events that cause congenital adrenal hyperplasia,2 3 4 5 patients with this disorder continue to have problems that reflect the inadequacy of current treatment.6 7 8 9 10 11 12 13 14 15 The response to treatment varies, and the excellent response in some patients should not obscure the need to improve treatment outcomes overall. This review addresses five questions concerning the pathophysiology and treatment of congenital adrenal . . .
Leydig cell hypoplasia (LCH) is a form of male pseudohermaphroditism in which Leydig cell differentiation and testosterone production are impaired. This report describes the first case of a nonsense mutation (A1635C) in exon 11 of the human luteinizing hormone receptor (hLHR) gene in two sisters with LCH. This mutation causes loss of function of the receptor by introducing a stop codon at residue 545 in transmembrane helix 5 of the hLHR. Surface expression of the truncated hLHR (hLHR-t545) in human embryonic kidney cells stably transfected with cDNA encoding hLHR-t545 was diminished compared to the wild-type hLHR and hCG-induced cAMP accumulation was impaired. These results establish that single base mutations in exon 11 of the hLHR gene can produce inactivation as well as activation of the hLHR. Furthermore, they demonstrate that functional domains between transmembrane helix 5 and the C-terminal cytoplasmic tail of the hLHR are required for normal cell surface expression of the receptor and signal transduction.
Because the pubertal growth spurt in boys appears to be mediated by both androgens and estrogens, we hypothesized that blockade of both androgen action and estrogen synthesis would normalize the growth of boys with familial male precocious puberty. To test this hypothesis, we studied nine boys (age range, 3.3 to 7.7 years) during treatment with an antiandrogen (spironolactone) or an inhibitor of androgen-to-estrogen conversion (testolactone), followed by treatment with both agents. After six months of observation without treatment, the first four boys received spironolactone for six months, followed by spironolactone and testolactone. The next five boys received testolactone for six months, followed by spironolactone and testolactone. Neither spironolactone nor testolactone, given alone, was satisfactory as a treatment for this condition. However, a combination of spironolactone and testolactone, given for at least six months, restored both the growth rate and the rate of bone maturation to normal prepubertal levels and controlled acne, spontaneous erections, and aggressive behavior. The combined therapy was associated with a significantly lower growth rate than testolactone alone (P less than 0.05) and a significantly lower rate of bone maturation than spironolactone alone (P less than 0.05). No important adverse effects were observed during combined treatment. Six of the nine boys continued to receive the combined therapy for an additional 12 months and maintained normal prepubertal rates of growth and bone maturation. The mean predicted height (+/- SEM) increased progressively during the combined treatment although the difference between the pretreatment and post-treatment predictions was not significant (169.5 +/- 2.8 at the end of treatment vs. 166.2 +/- 4.5 cm before treatment; P = 0.29). We conclude that blockade of both androgen action and estrogen synthesis with the combination of spironolactone and testolactone is an effective short-term treatment for familial male precocious puberty. Further study will be required, however, to assess the long-term outcome in boys who receive this treatment.
The glucocorticoid receptor antagonist RU 486 has been used to treat the hypercortisolism of patients with nonpituitary Cushing's syndrome. Since endogenous cortisol production fluctuates in many patients with either the ectopic ACTH syndrome or adrenocortical tumors, treatment of these patients with a fixed dose of RU 486 introduces the risk of adrenal insufficiency. While RU 486 possesses some glucocorticoid agonist activity in addition to its potent antagonist effects, it is not known whether this intrinsic agonist activity is of sufficient magnitude to prevent adrenal insufficiency and sustain life. To answer this question three groups of bilaterally adrenalectomized cynomolgus monkeys (n = 5/group) were randomized to receive a daily injection of RU 486 (5 mg/kg.day), cortisol (1.25 mg/kg.day), or saline (placebo). All adrenalectomized monkeys received weekly im injections of deoxycorticosterone pivalate (1 mg) to prevent mineralocorticoid deficiency. Five sham-adrenalectomized monkeys served as controls and received im injections of saline (placebo). Blood was collected before adrenalectomy or sham operation and every 3 days postoperatively for measurement of serum electrolytes, blood urea nitrogen, and creatinine; plasma ACTH concentrations; and complete blood and differential cell counts. All sham-operated and cortisol-replaced adrenalectomized monkeys survived, and none developed overt biochemical evidence of adrenal insufficiency. All placebo and RU 486-replaced adrenalectomized monkeys expired within 33 days after adrenalectomy, presumably from adrenal insufficiency. These findings suggest that while RU 486 is a partial glucocorticoid agonist, its degree of glucocorticoid agonism is inadequate to prevent adrenal insufficiency and support life in adrenalectomized primates.
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