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Background/Aim: The exon 3-deleted/full-length (d3/fl) growth hormone (GH) receptor (GHR) polymorphism has been associated with responsiveness to GH therapy in some diagnostic groups. However, there are still controversies on this issue. To evaluate the effect of the GHR exon 3 polymorphism on growth after 1 and 2 years of GH therapy in Turkish patients with GH deficiency (GHD) and Turner’s syndrome (TS) and the distribution of GHR exon 3 isoforms. Materials and Methods: 218 patients with GHD (125 males/93 females) and 43 patients with TS were included in the study. The control group included 477 healthy adults aged from 18 to 57 years (54 females/423 males). Anthropometric parameters and insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-3 were evaluated annually. GHR isoforms were studied using simple multiplex PCR. Height and body mass index were expressed as standard deviation score (SDS). Results: There were no differences among TS, GHD and healthy adults regarding the distribution of GHR exon 3 isoforms (fl/fl, fl/d3 and d3/d3). There was a significant increase in height SDS in both diagnostic groups on GH therapy; however, there were neither differences in height SDS and Δheight velocity between fl/fl, fl/d3 and d3/d3 groups nor a correlation between the distribution of GHR exon 3 isoforms and change in IGF-1 SDS and IGFBP-3 SDS levels on GH therapy in either of the diagnostic groups. There was also no gender difference in GHR isoforms in healthy adults. Conclusion: The results suggest that responsiveness to GH therapy does not depend on the exon 3 GHR genotypes in GHD and TS patients.

To assess the long-term effect of pamidronate therapy on bone mineral metabolism and bone mineral density (BMD) in children with osteogenesis imperfecta (OI) and to evaluate BMD results with respect to national standards.Pamidronate was administered intravenously on 3 consecutive days every 3 to 4 months at a dose of 1 mg/kg/d in 35 patients. Infusion cycles ranged from 4 to 17. Serum calcium, phosphorus, bone turnover markers, L1-L4 areal BMD (aBMD), and fracture rate were evaluated. Areal BMD Z scores were compared with national sex-specific reference data and volumetric BMD Z scores.In all children, linear growth continued along the same percentile during treatment. All parameters of bone turnover showed a decrease. L1 to L4 aBMD and Z score increased markedly, and fracture rate decreased in all patients during therapy. The mean annual percent gain in aBMD was highest in the first year and slowed down in subsequent years. Mean L1 to L4 aBMD Z scores according to Turkish reference data were higher than that of manufacturer values (P = 0.004). Correction of L1 to L4 vertebrae for bone size yielded to a decrease in osteoporosis in OI patients (41.5% vs 22.3%).Bone mineral density increased and fracture rate decreased in children and infants with OI during pamidronate treatment. Prevalence of osteoporosis decreased after correction for national standard and volumetric BMD. Use of an appropriate reference database and method of data analysis are very important for correct evaluation of osteoporosis.