285StudiesCanadian
study (2005)Toddler–Turner
study (2007) Dutch study (1999)
Height SDS after
rhGH therapy−0.2 to +1.4 SDS (TS
chart)−1.4 to −0.3 –Height SDS in
controls−0.1 to +0.2 SDS (TS
chart)−1.8 to −2.2 –Height gain + 7.2 cm – Group A: +12.5 cm
Group B: + 14.6 cm
Group C: +16 cm- Why are the doses of rhGH higher in children with Turner syndrome?
The doses of rhGH are relatively higher in children with TS as compared
to children with growth hormone deficiency. The recommended dose is
0.36–0.46 mg/Kg/week, administered daily at bedtime. This is because TS
is GH- resistant state due to intrinsic defect in chondrocytes as a result of
SHOX haploinsufficiency.- How to monitor a child with Turner syndrome receiving recombinant human
growth hormone therapy?
Patients with TS on rhGH therapy should be monitored at an interval of
3–6 months. Height should be monitored on standard growth chart. Doses of
rhGH can be adjusted according to growth response and serum IGF-1 levels,
which should be maintained in the mid-normal reference range. Kyphoscoliosis,
slipped capital femoral epiphysis, and benign intracranial hypertension are
more common in patients of TS treated with rhGH, and hence close surveil-
lance for these side effects is mandatory. Lack of optimal growth response to
rhGH therapy mandates evaluation for hypothyroidism and celiac disease, after
compliance to therapy has been ensured. Recombinant hGH therapy can be
discontinued after attainment of a near target height or a height velocity reduced
to <2 cm per year or bone age >14 years.- What are the predictors of response to rhGH therapy in patients with TS?
Younger age at initiation of therapy, higher doses of rhGH (0.375 mg/Kg/
week), prolonged duration of treatment, timely induction of puberty (approxi-
mately at 10–12 years of age), and greater genetic potential (target height) pre-
dict good response to rhGH therapy in patients with TS. However, karyotype of
the patient does not influence the response to rhGH therapy.8 Turner Syndrome