Endocrine Abstracts

JOINT2719

Introduction: SHOX deficiency and Turner syndrome are genetic disorders associated with short stature, both resulting from haploinsufficiency of the SHOX gene, which impairs growth. Despite their shared etiology, comparative data on the long-term efficacy of growth hormone (GH) therapy and final height (FH) outcomes remain limited. This study aims to retrospectively evaluate and compare the effects of GH therapy on FH in patients with SHOX deficiency and Turner syndrome.

Methods: This retrospective study included patients with genetically confirmed SHOX deficiency (n = 10) or Turner syndrome (n = 34) who had received GH therapy and attained their final height. Participants were prepubertal (Tanner stage 1) at the start of therapy and presented with a height below the 3rd percentile or between the 3rd and 10th percentiles with a growth velocity below the 25th percentile. Comparative analyses were conducted between the two groups, focusing on first- and second-year height velocities, height standard deviation (SD) scores, and overall height gain (cm).

Results: The ages at treatment initiation were similar between the SHOX deficiency and Turner syndrome groups (mean ± SD: 10. 7 ± 1. 9 years vs. 10. 4 ± 2. 7 years; P = 0. 967). The baseline height SD scores were −2. 66 ± 0. 8 in the SHOX deficiency group and −3. 5 ± 1. 07 in the Turner syndrome group, with the difference not reaching statistical significance (P = 0. 080). The gain in height SD score from the initiation of GH therapy to final height was comparable between the SHOX deficiency group (0. 07 ± 0. 35 [least-squares mean ± SE]) and the Turner syndrome group (0. 93 ± 0. 15). Importantly, the first-year height velocity was significantly higher in the SHOX deficiency group compared to the Turner syndrome group (mean ± SD: 8. 55 ± 1. 43 cm/year vs. 6. 72 ± 1. 99 cm/year; P = 0. 011). However, the second-year height velocity showed no significant difference between the groups (mean ± SD: 6. 63 ± 2. 29 cm/year vs. 5. 79 ± 1. 53 cm/year; P = 0. 203).

Conclusion: GH therapy leads to comparable long-term height improvements in patients with SHOX deficiency and Turner syndrome. However, patients with SHOX deficiency demonstrate a significantly greater height velocity during the first year of treatment.

Keywords SHOX deficiency, Turner syndrome, final height, growth hormone therapy