ESPE Abstracts

Introduction: Noonan syndrome (NS) and Turner syndrome (TS) are distinct genetic disorders with similarities in phenotype, including short stature. The NordiNet^® IOS and the ANSWER Program^® are observational studies evaluating effectiveness and safety of GH treatment in real-world practice.

Methods: The study population included children with NS or TS with puberty recordings, enrolled in NordiNet^® IOS or ANSWER^® Program. Start of puberty was defined as the midpoint between last prepubertal and first pubertal records. Physical evidence of puberty was defined clinically by Tanner breast stage ≥II or testicular volume ≥4 ml (or Tanner stage ≥GII).

Results: Mean age for puberty start in female NS patients (n=15) was 11.61±1.38 years; in male NS (n=37), 12.46±1.51 years; in TS (n=489), 12.91±1.87 years. Mean age at start of GH therapy in female NS was 9.21±3.18 years; in male NS, 10.34±2.67 years; in TS, 9.73±3.28 years. In 100 TS patients with documented sex hormone therapy, 45% received sex hormones before (mean time 0.49 years) and 55% (mean time 1.09 years) after start of clinical puberty. Mean age at start of GH therapy in TS patients given sex hormones before puberty was 9.51±3.58 years (puberty start 13.93±1.69 years) and 10.07±3.19 years in patients given sex hormones after start of puberty (puberty start 13.14±1.57 years). TS patients starting sex hormones after spontaneous puberty tended to be shorter (height SDS at baseline −2.78±0.99 vs −2.43±1.06) compared with those receiving sex hormones before puberty start, and age for sex hormone initiation was 14.23±1.52 vs 13.44±1.83 years.

Conclusions: This analysis suggests that clinical puberty onset in GH-treated NS and TS patients occurred within the normal population range. Some clinicians are confident to induce puberty in TS girls on GH therapy with exogenous sex hormone while a tendency to postpone sex hormone treatment in shorter TS patients has also been observed.