Effectiveness of the combined recombinant human growth hormone and gonadotropin-releasing hormone analog therapy in pubertal patients with short stature due to SHOX deficiency.

CONTEXT: Isolated heterozygous SHOX defects are the most frequent monogenic cause of short stature, and combined therapy with recombinant human GH (rhGH) and GnRH analog (GnRHa) in pubertal patients has been suggested, but there are no data on final height.
OBJECTIVE: The aim of the study was to analyze adult height after rhGH and GnRHa therapy in patients with SHOX haploinsufficiency. PATIENTS: Ten peripubertal patients with isolated SHOX defects participated in the study. INTERVENTION: Five patients were followed without treatment, and five were treated with rhGH (50 mug/kg/d) and depot leuprolide acetate (3.75 mg/month). MAIN OUTCOME MEASURES: Adult height sd score (SDS) was measured.
RESULTS: All patients followed without treatment had marked downward growth shift during puberty (height SDS, -1.2 +/- 0.7 at 11.4 +/- 1.4 yr; adult height SDS, -2.5 +/- 0.5). Conversely, four of five patients treated with rhGH for 2 to 4.9 yr associated to GnRHa for 1.4 to 5.8 yr improved their height SDS from -2.3 +/- 1.3 at 11.8 +/- 2.1 yr to a final height SDS of -1.7 +/- 1.6. The difference between the mean height SDS at the first evaluation and final height SDS was statistically significant in nontreated vs. treated patients (mean height SDS change, -1.2 +/- 0.4 vs. 0.6 +/- 0.4, respectively; P <0.001).
CONCLUSION: A gain in adult height of patients with isolated SHOX defects treated with combined rhGH and GnRHa therapy was demonstrated for the first time, supporting this treatment for children with SHOX defects who have just started puberty to avoid the loss of growth potential observed in these patients during puberty.