287with rhGH resulted in an additional height gain of 2.1 cm as compared to rhGH
therapy alone.- How is oxandrolone helpful in promoting linear growth in children with TS?
Oxandrolone is a non-aromatizable androgen which is administered orally. At a
dose of 0.05 mg/Kg/day (maximum dose 2.5 mg/day), it has been shown to be
effective in promoting linear growth in children with TS. The mechanism of
growth-promoting action of oxandrolone is not well understood. The proposed
mechanism includes increase in GH secretion and/or IGF1 generation. The side
effects of oxandrolone include hypertension, hepatotoxicity, virilization, and
regression of breast development.- When to induce puberty in girls with Turner syndrome?
In normal girls, puberty starts by the age of 8–13 years. In children with TS,
the recommended age for the induction of puberty is 12 years. This age is
chosen as it has been shown that induction of puberty with low-dose estrogen
at this age does not interfere with growth-promoting effects of GH (as it pro-
motes IGF1 generation). Further, low-dose estrogen therapy at this age does
not influence bone maturation. In addition, waiting till 12 years of age also
gives an opportunity to watch for spontaneous puberty which occurs in
10–20 % of children with TS. In the past, delaying the induction of puberty till
14–15 years was thought to improve the final height; however, it is no longer
recommended as this results in adverse effects on psychosocial development
and bone mineral density.- How to induce puberty in girls with TS?
Before initiating estrogen for induction of puberty, serum FSH levels should
be determined to confirm gonadal failure. Puberty can be induced by estro-
gen, which can be administered either through oral, transdermal, or intramus-
cular (depot) route; however, transdermal route is preferred. Oral estrogen
therapy is initiated with estradiol valerate or micronized estradiol at dose of
0.25 mg/day or ethinyl estradiol 5 μg/day or conjugated equine estrogen
0.162 mg/day. The initiating dose for transdermal estradiol is 6.25 μg/day.
The dose should be gradually titrated up at every 3–6 months interval, so that
the adult dose (2 mg estradiol valerate or equivalent) is reached over a period
of 2–4 years. Progesterone should be added once breakthrough bleed occurs
or after at least 2 years of estrogen therapy. Later, the treatment should be
maintained with estrogen and progesterone administered cyclically. The dose
of estrogen should be reduced to 1 mg of estradiol valerate or its equivalent
beyond the age of 30 years. Hormone replacement therapy should be contin-
ued up to the age of menopause for that ethnic group or till 50 years.8 Turner Syndrome