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Inherited GH insensitivity (GHI) is usually caused by mutations in the GH receptor (GHR). Patients present with short stature associated with high GH and low IGF-I levels and may have midfacial hypoplasia (typical Laron syndrome facial features). We previously described four mildly affected GHI patients with an intronic mutation in the GHR gene (A(-1)--G(-1) substitution in intron 6), resulting in the activation of a pseudoexon (6Psi) and inclusion of 36 amino acids.The study aimed to analyze the clinical and genetic characteristics of additional GHI patients with the pseudoexon (6Psi) mutation.Auxological, biochemical, genetic, and haplotype data from seven patients with severe short stature and biochemical evidence of GHI were assessed.We assessed genotype-phenotype relationship.One patient belongs to the same extended family, previously reported. She has normal facial features, and her IGF-I levels are in the low-normal range for age. The six unrelated patients, four of whom have typical Laron syndrome facial features, have heights ranging from -3.3 to -6.0 sd and IGF-I levels that vary from normal to undetectable. We hypothesize that the marked difference in biochemical and clinical phenotypes might be caused by variations in the splicing efficiency of the pseudoexon.Activation of the pseudoexon in the GHR gene can lead to a variety of GHI phenotypes. Therefore, screening for the presence of this mutation should be performed in all GHI patients without mutations in the coding exons.

Children with idiopathic short stature (ISS) may have normal or increased growth hormone (GH) responses to provocation tests and achieve a final height (FH) below –2.0 standard deviation score (SDS) if untreated. FH of subjects with high stimulated GH levels has not been studied in detail. Aim: It was the aim of this study to analyse FH in ISS patients with high GH peak responses to the provocation test. Patients andMethods: We studied 16 patients (9 pre-pubertal) with ISS and a GH peak ≧40 mU/l to insulin-induced hypoglycaemia. The patients were recalled at age 19.7 ± 2.5 years for measurement of FH when blood samples were obtained for serum insulin-like growth factor (IGF)-I, IGF binding protein 3, acid-labile subunit and GH binding protein measurements. GH bioactivity was determined using the Nb2 bioassay. Results: FH was –3.1 ± 1.0 SDS, being significantly lower than target height (TH). At FH, IGF-I levels were within –1.5 and +1.5 SDS for age and sex in 10 patients and higher than +1.5 SDS in 6 patients. IGF binding protein 3, acid-labile subunit, GH binding protein levels and GH bioactivity values were normal. Summary: These data suggest that patients with ISS and high GH levels during a GH stimulation test may have a more compromised FH. The association of severe ISS with a peak GH >40 mU/l might suggest a degree of insensitivity for the GH-IGF-I axis.

Context: Patients with panhypopituitarism have impaired quality of life (QoL) despite GH replacement. They are profoundly androgen deficient, and dehydroepiandrosterone (DHEA) has been shown to have a beneficial effect on well-being and mood in patients with adrenal failure and possibly in hypopituitarism.Objective: Our objective was to determine the effect of DHEA administration on mood in hypopituitary adults on established GH replacement with a constant serum IGF-I.Design: A double-blind, placebo-controlled trial was conducted over an initial 6 months followed by an open phase of 6 months of DHEA.Setting: The study was conducted at a tertiary referral endocrinology unit.Patients: Thirty female and 21 male hypopituitary patients enrolled. Data from 26 females and 18 males were analyzed after patient withdrawal.Interventions: DHEA (50 mg) was added to maintenance replacement including GH.Main Outcome Measures: The primary outcome objective was the effect on QoL and libido assessed by QoL assessment in GH deficiency in adults, Short Form 36, General Health Questionnaire, EuroQol, and sexual self-efficacy scale.Results: Patients had impaired QoL at baseline compared with the age-matched British population. Females showed improvement in QoL assessment in GH deficiency in adults score (−2.9 ± 2.8 DHEA vs.−0.53 ± 3 placebo; P < 0.05), in Short Form 36 social functioning (14.6 ± 23.1 DHEA vs.−4.7 ± 25 placebo; P = 0.047), and general health perception (9.6 ± 14.2 DHEA vs.−1.2 ± 11.6 placebo; P = 0.036) after 6 months of DHEA. Men showed improvement in self-esteem (−1.3 ± 1.7 DHEA vs. 0.5 ± 1.5 placebo; P = 0.03) and depression (−1.6 ± 2.2 DHEA vs. 1.2 ± 2.4 placebo, P = 0.02) domains of the General Health Questionnaire after 6 months of DHEA.Conclusions: DHEA replacement leads to modest improvement in psychological well-being in female and minor psychological improvement in male hypopituitary patients on GH replacement.

Chronic inflammation is characterised by modifications in cytokine concentrations, whereas growth is mainly dependent on the GH-IGF axis. IGF-I bioavailability is modulated by a family of IGF-binding proteins (IGFBPs). The aim of the present study was to evaluate the interactions among interleukin-1beta (IL-1beta), IL-6 and IGFBP secretion by intestinal cells to assess whether cytokines modulate IGFBP secretion, and in turn IGF-I and IGF-II bioavailability. The human colon carcinoma derived cell line Caco-2 was used as an in vitro model for its capacity to differentiate spontaneously. Experiments were carried out on day 4 (undifferentiated state) and day 14 (differentiated state) after plating. Carcinoembryonic antigen (CEA) was used as a marker of differentiation and increased in the conditioned media (CM) from days 4 to 14 (0.2+/-0.01 ng/ml per 10(5) cells vs 3.3+/-0.2 ng/ml per 10(5) cells, P

Measurement of the insulin-like growth factors (IGFs) and their binding proteins has become commonplace in the indirect assessment of the integrity of the GH axis. However, the relative effect of GH deficiency (GHD) on each component of the IGF axis and the merit of any one parameter as a diagnostic test have not been defined in a homogeneous population across all ages. We therefore measured IGF-I, IGF-II, IGF-binding protein-1 (IGFBP-1), IGFBP-2, IGFBP-3, and acid labile subunit (ALS) in 27 GHD subjects (aged 5–82 yr) from an extended kindred in Northeast Brazil with an identical GHRH receptor mutation and in 55 indigenous controls (aged 5–80 yr). The effect of GHD on the theoretical distribution of IGFs between the IGFBPs and the ternary complex was also examined. All components of the IGF axis, measured and theoretical, showed complete separation between GHD and control subjects, except IGFBP-1 and IGFBP-2 concentrations, which did not differ. The most profound effects of GHD were on total IGF-I, IGF-I in the ternary complex, and ALS. The proportion of IGF-I associated with IGFBP-3 remained constant throughout life, but was significantly lower in GHD due to an increase in IGF-I/IGFBP-2 complexes. IGF-I in the ternary complex was determined principally by concentrations of ALS in GHD and IGFBP-3 in controls, implying that ALS has greater GH dependency. In the controls, IGF-II was associated primarily with IGFBP-3 and to a lesser extent with IGFBP-2, whereas in GHD the reverse was found. There was also a dramatic decline in the proportion of free ALS in GHD adults that was not evident in controls. As diagnostic tests, IGF-I in the ternary complex and total IGF-I provided the greatest separation between GHD and controls in childhood. Similarly, in older adults the best separation was achieved with IGF-I in the ternary complex, with free ALS being optimal in younger adults. Severe GHD not only reduces the amounts of IGFs, IGFBP-3, and ALS, but also modifies the distribution of the IGFs bound to each IGFBP. Diagnostic tests used in the investigation of GHD should be tailored to the age of the individual. In particular, measurement of IGF-I in the ternary complex may prove useful in the diagnosis of GHD in children and older adults, whereas free ALS may be more relevant to younger adults.

Insulin-like growth factor-I (IGF-I) is one of the most important regulator of growth. IGF-I deficiency is associated with prenatal and post-natal growth failure and may arise primarily as a result of GH receptor/post-receptor abnormalities or defects in the synthesis and transport of IGF-I. We have previously reported a 17.2-year-old boy with severe growth retardation and undetectable serum levels of IGF-I caused by a partial deletion of the IGF-I gene. This short review will concentrate on results of a recent study which examined the effects of rhIGF-I therapy on the GH-IGF system of this patient. Similar to healthy individuals, this patient had normal IGFBP-3 but elevated ALS levels. IGF-I treatment has improved linear growth and insulin sensitivity in this patient by restoring IGF-I levels and by normalizing circulating GH, IGFBPs and insulin levels.

ObjectiveGH insensitivity (GHI) is caused in the majority of cases by impaired function of the GH receptor (GHR). All but one knownGHRmutation are in the coding sequence or the exon/intron boundaries. We identified and characterised the first intronic defect occurring in the polypyrimidine tract of theGHRin a patient with severe GHI.DesignWe investigated the effect of the novel defect on mRNA splicing using anin vitrosplicing assay and a cell transfection system.MethodsGHRwas analysed by direct sequencing. To assess the effect of the novel defect, two heterologous minigenes (wild-type and mutant L1-GHR8-L2) were generated by insertingGHRexon 8 and its flanking wild-type or mutant intronic sequences into a well-characterised splicing reporter (Adml-par L1–L2).32P-labelled pre-mRNA was generated from the two constructs and incubated in HeLa nuclear extracts or HEK293 cells.ResultsSequencing of theGHRrevealed a novel homozygous defect in the polypyrimidine tract of intron 7 (IVS7-6T>A). This base change does not involve the highly conserved splice site sequences, and is not predictedin silicoto affect GHR mRNA splicing. Nevertheless, skipping of exon 8 from the mutant L1-GHR8-L2 mRNA was clearly demonstrated in thein vitrosplicing assay and in transfected HEK293 cells.ConclusionDisruption of theGHRpolypyrimidine tract causes aberrant mRNA splicing leading to a mutant GHR protein. This is predicted to lack its transmembrane and intracellular domains and, thus, be incapable of transducing a GH signal.

Summary Objective GH dose requirement is lower in ACTH replete compared with ACTH deficient hypopituitary patients suggesting that adrenal androgens may augment IGF-I generation for a given GH dose. This study aimed to determine the effect of dehydroepiandrosterone (DHEA) administration on GH dose requirements in hypopituitary adults. Design A double blind placebo controlled trial was conducted adding 50 mg DHEA to the standard replacement of hypopituitary patients, including GH, over an initial 6 months, followed by an open phase study of 6 months DHEA replacement and a final 2 month washout phase after DHEA withdrawal. The dose of GH was adjusted to achieve a constant serum IGF-I. Patients Thirty female and 21 male hypopituitary patients were enrolled. Data from 26 women and 18 men were analysed after patient withdrawal. Measurements The primary outcome objective was the GH dose required to achieve a stable serum IGF-I. Secondary outcome measures were lipoprotein profiles, insulin, insulin sensitivity, IGFBP-3, waist/hip ratio and indices of bone remodelling. Results DHEA replacement in female patients lead to a 14·6 ± 20% reduction in the dose of GH for a constant serum IGF-I (P

CONTEXT: Non-islet cell tumor hypoglycemia (NICTH) results from the hypersecretion of pro-IGF-II by a large, usually mesenchymal tumor. Detection of pro-IGF-II in serum is a potential tumor marker in these patients. OBJECTIVE: The aim of this study was to validate a rapid and reliable method for determining serum pro-IGF-II. PATIENTS: Serum samples from 16 patients with NICTH were studied. MAIN OUTCOME MEASURE: The main outcome measure was serum concentration of pro-IGF-II determined by immunoblot analysis of pro-IGF-II and mature IGF-II after 16.5% tricine-SDS-PAGE, which was compared with pro-IGF-II measured by standard RIA after size-exclusion acid chromatography. RESULTS: The analyses of patients' sera by size-exclusion acid chromatography showed that 68 +/- 19% of IGF-II were present in the pro-IGF-II form, whereas only 18 +/- 4% corresponded to pro-IGF-II in controls. Scanning densitometry of immunoblots showed 67 +/- 16% in the bands corresponding to pro-IGF-II in patients' sera, compared with 27 +/- 9% in controls. The detection sensitivity of tricine-SDS-PAGE method was the same as for size-exclusion chromatography, but the tricine-SDS-PAGE method is quicker and requires smaller amounts of serum. CONCLUSION: Tricine-SDS-PAGE followed by IGF-II immunoblot analysis provides a rapid, reproducible, and sensitive method for the separation of serum pro-IGF-II from mature IGF-II and is a useful laboratory evaluation of patients with a clinical diagnosis of NICTH.

We report a female child who presented at age 3.92 years with a 2-year history of consonant pubertal development caused by a large right-sided ovarian juvenile granulosa cell tumour (JGCT). Although JGCTs causing pseudo-precocious puberty have been previously described, they remain rare and endocrine data are often incomplete. In this case the tumour was associated with raised serum oestradiol, androstenedione, inhibin and IGF-I. Histological changes were consistent with JGCT. Immunohistochemical studies revealed positive reactivity to MIC-2, inhibin, melan A, IGF-I and IGFBP-2.

We have previously reported a 17.2-yr-old boy with severe growth retardation and undetectable serum levels of insulin-like growth factor I (IGF-I) due to a partial deletion of the IGF-I gene. The aim of this study was to investigate the effects of recombinant human IGF-I (rhIGF-I) therapy on the GH-IGF system of this patient to gain further insights into its growth-promoting and metabolic actions. To assess the changes in GH, IGFs, IGF-binding proteins (IGFBPs), acid-labile subunit (ALS), and insulin levels, blood samples were obtained before therapy and during the first year of treatment. Hormones were analyzed by specific RIAs. Overnight GH profiles were performed before and at 1, 6, and 12 months of therapy. Fasting ALS, IGF-II, IGFBP-3, IGFBP-2, IGFBP-1, and insulin levels before rhIGF-I treatment were 46.3 mg/L, 1044 microg/L, 5.8 mg/L, 73 ng/mL, 4.7 ng/mL, and 27.3 mU/L, respectively. IGF-II, ALS, and insulin levels were elevated, whereas IGFBP-1 and IGFBP-2 levels were decreased compared to reference values. Twenty-four hours after a single s.c. injection of rhIGF-I (40 microg/kg), the concentrations were 46 mg/L, 888 microg/L, 6.9 mg/L, 112 ng/mL, 5.0 ng/mL, and 21.0 mU/L, respectively. After a single s.c. injection of rhIGF-I of 40 or 80 microg/kg x day and modelling the data using a two-compartment model, the half-lives of elimination were 15.7 and 14.3 h, with a maximum increase in IGF-I levels to 341 and 794 microg/L around 7 h, respectively. An increase in IGFBP-3 levels was observed with both doses of rhIGF-I, with a peak values of 9 mg/L. GH profiles showed a decrease in peak amplitude from 342 to 84 mU/L at 1 month, to 67 mU/L at 6 months, and to 40 mU/L at 1 yr of therapy, with no significant changes in peak number. A significant increase in IGFBP-1 levels was observed during treatment with 80 microg/kg x day IGF-I, reflecting the inhibitory effect of rhIGF-I on insulin secretion. The clinical response to rhIGF-I therapy was an increased height velocity from 3.8 cm/yr before treatment to 6.6 cm/yr. Increased lean body mass correlated with changes in the doses of rhIGF-I and, in turn, with the biochemical changes in the GH-IGF axis. Similar to healthy individuals, this patient had normal IGFBP-3 and ALS levels, which are the major regulators of the pharmacokinetics of rhIGF-I. In summary, rhIGF-I treatment has improved linear growth and insulin sensitivity in this patient by restoring IGF-I levels and by normalizing circulating GH, IGFBP, and insulin levels.