ESPE Abstracts

Background: Despite different genetic backgrounds, Noonan syndrome (NS) shares similar phenotype features to Turner syndromes (TS) such as short stature, webbed neck and congenital heart defects. The primary cause of short stature in Turner syndrome and Noonan syndrome is GH resistance [1]. Recombinant human growth hormone (rhGH) is being used to promote linear growth in short children with Noonan syndrome. However, its efficacy is still controversial.

Aims: It was aimed to evaluate the effect of rhGH treatment on first-year response and adult height in children with Noonan and Turner syndrome.

Methods: Forty-eight patients (ten children diagnosed with NS (three patients diagnosed genetically), thirty-eight diagnosed with TS) data were retrospectively retrieved from the hospital’s records consisting of patients’ receiving growth hormone therapy.

Results: In Noonan Syndrome; the mean (SD) baseline age was 12.4 (± 2.4) years; HSDS, -3.6 (± 0.7), GH dose, 30 µg/kg/day. The mean (SD) HSDS increase from baseline (ΔHSDS) was 0.47 (±0.43) was. Six patients achieved NAH. The mean (SD) NAH SDS (NR) was -0.44 (± 3.7) (150.4 cm) in females and -2.96 (± 0.26) (158.1 cm) in males. In Turner Syndrome; the mean (SD) baseline age was 9.9 (± 3.3) years (P<0.05); HSDS, -3.4 (± 0.8), GH dose, 44 µg/kg/day (P<0.05). The mean (SD) HSDS increase from baseline (ΔHSDS) was 0.43 (±0.94) was. Sixteen patients achieved NAH. The mean (SD) NAH SDS (NR) was -2.4(± 1.4) (148.8 cm). The changes in height velocity or height SDS in the first year and Near-adult height were not related to the age, gender, height deficit or a delay in bone age maturation at the start of treatment, level of IGF-1 and IGFBP3 and IGF-1/IGFBP3 ratio.

Conclusion: We found children with NS to have a better growth response to treatment with rhGH than girls with TS. We had similar height velocity in NS with IGF-1 which increased less than TS. Effective treatment can be achieved with personalized doses.