Background: Short stature affects approximately 2% of children, representing one of the more frequent disorders for which clinical attention is sought during childhood. Despite assumed genetic heterogeneity, mutations or deletions of the short stature homeobox-containing gene (SHOX) are found quite frequently in subjects with short stature. Haploinsufficiency of the SHOX gene causes short stature with highly variable clinical severity, ranging from isolated short stature without dysmorphic features to Léri-Weill syndrome, and with no functional copy of the SHOX gene, Langer syndrome. Methods: To characterise the clinical and molecular spectrum of SHOX deficiency in childhood we assessed the association between genotype and phenotype in a large cohort of children of short stature from 14 countries. Results: Screening of 1608 unrelated individuals with sporadic or familial short stature revealed SHOX mutations or deletions in 68 individuals (4.2%): complete deletions in 48 (70.6%), partial deletions in 4 (5.9%) and point mutations in 16 individuals (23.5%). Although mean height standard deviation score (SDS) was not different between participants of short stature with or without identified SHOX gene defects (-2.6 vs -2.6), detailed examination revealed that certain bone deformities and dysmorphic signs, such as short forearm and lower leg, cubitus valgus, Madelung deformity, high-arched palate and muscular hypertrophy, differed markedly between participants with or without SHOX gene defects (p,0.001). Phenotypic data were also compared for 33 children with Turner syndrome in whom haploinsufficiency of SHOX is thought to be responsible for the height deficit. Conclusion: A phenotype scoring system was developed that could assist in identifying the most appropriate subjects for SHOX testing. This study offers a detailed genotype-phenotype analysis in a large cohort of children of short stature, and provides quantitative clinical guidelines for testing of the SHOX gene.

GH treatment in children with GH deficiency is frequently terminated at final height. However, in healthy individuals bone mass continues to accrue until peak bone mass is achieved. Because no prospective data specifically prove the role of GH in attainment of peak bone mass, we performed a multinational, controlled, 2-yr study in patients who had terminated pediatric GH at final height. Patients were randomized to: GH at 25.0 microg/kg x day (pediatric dose, n = 58) or 12.5 microg/kg x day (adult dose, n = 59), or no GH treatment (control, n = 32). Bone mineral content (BMC) and density were measured by dual-energy x-ray absorptiometry and evaluated centrally. Laboratory measurements were also performed centrally. After 2 yr, significant increases were seen with both GH treatments, compared with control in bone-specific alkaline phosphatase (P = 0.004) and type I collagen C-terminal telopeptide:creatinine ratio (P < 0.001), but there were no significant dose effects. Total BMC increased by 9.5 +/- 8.4% in the adult dose group, 8.1 +/- 7.6% in the pediatric dose group, and 5.6 +/- 8.4% in controls (analysis of covariance, P = 0.008), with no significant GH dose effect. BMC increased predominantly at the lumbar spine (11.0 +/- 10.6%, P = 0.015) rather than at the femoral neck or hip. In contrast, a significant dose-dependent increase was seen in IGF-I concentrations (adult dose: 114.5 +/- 119.4 microg/liter; pediatric dose: 178.5 +/- 143.7 microg/liter; P = 0.023). There were no gender-related differences in BMC changes with either dose, whereas the IGF-I increase was significantly higher with the pediatric than with the adult dose in females (P < 0.001) but not males (P = 0.606). In summary, reinstitution of GH replacement after final height in severely GH-deficient patients induced significant progression toward peak bone mass. Although there was a by-gender dose effect on IGF-I concentration, the treatment effect on bone was obtained in both males and females with the adult GH dose regimen.

Context: A variant of the human GH receptor (GHR) lacks a 22-amino-acid sequence derived from exon 3 (d3-GHR). It was reported that pediatric patients, born small for gestational age or with idiopathic short stature who were homozygous or heterozygous for this variant responded better to GH treatment than those homozygous for the full-length allele (fl-GHR). Objective:The objective was to study the impact of the GHR genotype on the phenotype and growth response in patients with isolated GH deficiency (IGHD) treated with GH.Design: This was a retrospective, multinational, multicenter observational study. Patients:Patients with IGHD (n ϭ 107) were recruited.Interventions: All patients received GH treatment at replacement doses. The GHR genotype (fl-GHR/fl-GHR, fl-GHR/d3-GHR, or d3-GHR/d3-GHR) was determined by PCR amplification. Main Outcome Measures:Measures included height SD score, height velocity, height velocity SD score at baseline and 1 yr of GH treatment, and their changes.Results: There was no statistically significant difference of the main outcome measures between patients with the d3-GHR allele (n ϭ 48) and patients who were homozygous for the fl-GHR allele (n ϭ 59). Moreover, the genotype group did not contribute significantly to the growth prediction in multiple linear regression models. Conclusions:Our results indicate that the d3-GHR allele does not affect response to GH treatment or contribute to growth predictions in patients with IGHD who received replacement doses of GH aiming to restore a normal GH status. We did not confirm the previously reported data obtained in patients small for gestational age or with idiopathic short stature who received supraphysiological GH doses.

Questions on Life Satisfaction-Hypopituitarism (QLS-H) is a new quality-of-life (QoL) questionnaire developed for adults with hypopituitarism. To determine the effects of long-term GH treatment on QoL, we evaluated QLS-H Z-scores in 576 adult patients with GH deficiency (GHD) enrolled in HypoCCS, an international observational study, using data from five countries in which comparative QLS-H data from the general population were available. Baseline QLS-H Z-scores were significantly lower in GH-deficient patients than in the general population of the same age, gender, and nationality. Z-scores were also significantly lower in female patients vs. males (P = 0.006) and in adult-onset vs. childhood-onset GHD (P = 0.002). Multivariate analysis associated female gender, multiple pituitary hormone deficiencies, low serum IGF-I values (<75 micro g/liter), and concomitant antidepressant medication with low baseline Z-scores. QLS-H Z-scores increased from -1.02 +/- 1.43 (SD) at baseline to -0.25 +/- 1.34 (SD) after 1 yr of GH treatment (P < 0.001) and were no longer significantly different from the general population after 4 yr of treatment. There was no correlation between change in Z-score and GH dose or changes in IGF-I and IGF binding protein-3 during treatment. This study demonstrates that 1) improvements in QoL, as measured by the QLS-H, are maintained during long-term GH replacement therapy of adults with GHD, and 2) the QLS-H is a useful tool for evaluating QoL in hypopituitary patients treated in clinical practice. The authors suggest that evaluation of QoL should be a part of the routine clinical management of adult GH-deficient patients, complementing the measurement of surrogate biological markers or other clinical end points.

Lean body mass (LBM), fat mass (FM), and total bone mineral content are significantly reduced in adult GHD subjects who had received pediatric GH. To test the hypothesis that continued GH therapy after final height is necessary to attain adult body composition, we performed a prospective, multinational, randomized, controlled, 2-yr study in patients who completed pediatric GH treatment at final height. Patients were randomized to GH at 25.0 microg/kg x d (pediatric dose; n = 58) or 12.5 microg/kg x d (adult dose; n = 59) or no GH treatment (control; n = 32). LBM and FM were measured by dual energy x-ray absorptiometry and were centrally evaluated. IGF-I, IGF-binding protein-3, and lipid concentrations were also measured centrally. During the 2 yr, GH-treated patients gained a significant amount of LBM compared with controls (P < 0.001), but the change with the higher pediatric dose (14.2 +/- 11.7%) was not different from that seen with the lower adult dose (12.7 +/- 9.4%; P = 0.970). Similarly, the decrease in FM was significantly (P = 0.029) influenced by treatment, but with no dose effect (adult dose, -7.1 +/- 22.8%; pediatric dose, -6.0 +/- 26.6%; P = 0.950). When the GH treatment effect was analyzed by gender, males gained 15.6 +/- 9.8% and 14.3 +/- 11.7% LBM (P = 0.711) and lost 12.4 +/- 22.2% and 11.0 +/- 27.1% FM (P = 0.921) with the low and high doses, respectively. Females gained 8.3 +/- 7.3% and 12.5 +/- 12.8% LBM with the two doses (P = 0.630), but increased their FM by 3.5 +/- 16.2% with the lower dose and lost only 1.2 +/- 23.2% FM with the higher dose (P = 0.325). A similar pattern was seen in IGF-I sd score; the 2-yr GH dose response was significantly higher with the pediatric than with the adult dose in females (P = 0.008), but not males (P = 0.790). The divergent pattern of change in LBM and FM in males and females is consistent with normal developmental sexual dimorphism and indicates that GH-dependent progress to target body composition continues after the age at which GH treatment is usually terminated. Dose requirements may have to be adjusted by gender, with females requiring a higher dose than males.