Context: In short SGA patients, the exon 3-deleted (d3)/full-length (fl)-GHR polymorphism was associated with responsiveness to GH therapy (30–48 µg/kg/d); however, these results were not confirmed for higher GH doses (56–66 µg/kg/d). We hypothesized that higher doses would mask the lower dose differences.

Objective: The objective was to evaluate, in short SGA patients, two-year growth response to GH therapy (32.1 ± 3.8 µg/kg/d) according to exon 3-deleted/full-length-GHR genotypes.

Setting: Two-year follow-up study.

Patients: Sixty short SGA children (d3/d3 n = 8, d3/fl n = 23, fl/fl n = 29). Eleven entered puberty during the second follow-up year. Results were evaluated for all patients (group A1, n = 60, 7.7 ± 2.7 yr) and for patients who remained prepubertal (group A2, n = 49, 6.9 ± 2.2 yr).

Main Outcome Measures: Patients were followed by a single clinical team and exon 3-deleted/full-length-GHR genotypes were determined and analyzed in the same hospital.

Results: In groups A1 and A2, growth velocity significantly (P < 0.0001) increased during the first and second years of therapy, as did height-SDS. These increases were similar in each exon 3-deleted/full-length-GHR genotype. Total two-year height gain (cm, SDS) did not differ statistically among genotypes: Group A1: 15.0 ± 2.0 cm and 1.15 ± 0.45 SDS in d3/d3; 16.0 ± 2.4 cm and 1.17 ± 0.51 SDS in d3/fl; 16.1 ± 2.4 cm and 1.15 ± 0.53 SDS in fl/fl; Group A2: 15.4 ± 2.0 cm and 1.03 ± 0.42 SDS in d3/d3; 15.6 ± 2.1 cm and 1.22 ± 0.51 in d3/fl and 16.2 ± 2.6 cm and 1.21 ± 0.56 SDS in fl/fl.

Conclusions: These results did not confirm our hypothesis and show that, in short SGA children, 2-yr growth response to GH therapy 32.1 ± 3.8 µg/kg/d was similar for each exon 3-deleted/full-length-GHR genotype carried, as occurred in our previous study using 66 µg/kg/d.