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tone. The rationale of rhGH therapy in these individuals is to counteract the
effects of glucocorticoids on linear growth. Therapy with rhGH and GnRH ago-
nists or rhGH alone has been shown to increase height by 1 SDS (7 cm). In a
small study, it has also been shown that combination therapy with fl utamide and
testolactone for 2 years resulted in restoration of normal growth velocity and
deceleration in bone maturation. However, therapy with these agents is consid-
ered experimental as limited data is available regarding their effi cacy and safety
and may be considered if the predicted adult height of a child is ≤−2.25 SD.- When to suspect the onset of GDPP in a child with CAH on therapy with
glucocorticoids?
Onset of thelarche in girls and testicular enlargement in boys are the clinical
clues to suspect the onset of GDPP after initiation of glucocorticoid therapy for
CAH. Those children with CAH who have advanced bone age (>11–12 years)
at initiation of therapy are at a higher risk for the development of GDPP, as the
advanced bone age is a surrogate evidence of maturation of hypothalamo–pitu-
itary–gonadal axis. The onset of GDPP can be confi rmed by estimation of basal
LH (≥0.3 μIU/ml) and LH response to GnRH (≥5–8 μIU/ml). Timely recogni-
tion of GDPP is important because untreated children with GDPP have com-
promised fi nal adult height. In addition, psychosocial distress associated with
progression of puberty can also be prevented.- Why does gonadotropin-dependent precocious puberty occur in children with
CAH?
The onset of gonadotropin-dependent precocious puberty in children with CAH
commonly occurs after the initiation of therapy, especially in those where ther-
apy was delayed. This is because abrupt lowering of persistently elevated sex
steroids after initiation of therapy (for long-standing untreated CAH) results in
premature reactivation of a primed HPG-axis.- What are the causes of reduced growth velocity in a child with CAH who devel-
oped GDPP and is on therapy with glucocorticoids and GnRH agonists?
In this scenario, the reduced growth velocity can be due to either overtreat-
ment with glucocorticoids or GnRH agonists. Estimation of serum 17(OH)P,
androstenedione, testosterone/estradiol, and LH helps in differentiating
between the two. A serum 17(OH)P level below the recommended range sug-
gests overtreatment with glucocorticoids. In a child with reduced growth
velocity while on therapy with glucocorticoids and GnRH agonists, sup-
pressed testosterone/estradiol and LH, while 17(OH)P in the recommended10 Congenital Adrenal Hyperplasia