scholarly journals PTPN11 Mutations Are Associated with Mild Growth Hormone Resistance in Individuals with Noonan Syndrome

2005 ◽  
Vol 90 (9) ◽  
pp. 5377-5381 ◽  
Author(s):  
G. Binder ◽  
K. Neuer ◽  
M. B. Ranke ◽  
N. E. Wittekindt

Abstract Context: Noonan syndrome is frequently associated with an unclear disturbance of GH secretion. Half the individuals with Noonan syndrome carry a heterozygous mutation of the nonreceptor-type protein tyrosine phosphatase, Src homology region 2-domain phosphatase-2 (SHP-2), encoded by PTPN11, which has a role in GH receptor signaling. Objective: The objective of this study was to compare GH secretion and IGF-I/IGF-binding protein-3 (IGFBP-3) levels of the SHP-2 mutation-positive (mut+ group) vs. mutation-negative individuals (mut− group). Design, Setting, and Patients: All children presenting to us with short stature plus at least three typical anomalies of Noonan syndrome or pulmonic stenosis during the last 5 yr (n = 29; 10 females and 19 males) were recruited. Auxological data, dysmorphic features, and cardiac morphology were documented. Hormone levels were measured by RIA. All coding exons of PTPN11 were sequenced after PCR amplification. Intervention: A prepubertal subgroup (n = 11) was treated with recombinant human GH (rhGH) to promote growth. Results: Sequencing yielded 11 different PTPN11 missense mutations in 16 of the 29 patients (55% mut+). Pulmonic stenosis (81 vs. 15%; P = 0.0007) and septal defects (63 vs. 15%; P = 0.02) were more frequently found in the mut+ group, whereas minor anomalies, cryptorchidism, and learning disabilities were as frequent in the mut+ group as in the mut− group. The mut+ group was younger at presentation (mean ± sd, 5.1 ± 2.7 vs. 10.3 ± 5.2 yr; P = 0.002), but not significantly shorter [−3.15 ± 0.92 vs. −3.01 ± 1.35 height sd score (SDS)]. IGF-I levels (−2.03 ± 0.69 vs. −1.13 ± 0.89 SDS; P = 0.005) and IGFBP-3 levels (−0.92 ± 1.26 vs. 0.40 ± 1.08 SDS; P = 0.006) were significantly lower in the mut+ group. In contrast, GH levels showed a tendency to be higher in the mut+ group during spontaneous secretion at night and arginine stimulation (P ≥ 0.075, not significant). The mean change in height SDS after 1 yr of rhGH therapy (0.043 mg/kg·d) was +0.66 ± 0.21 in the mut+ group (n = 8), but +1.26 ± 0.36 in the mut− group (n = 3; P = 0.007). Conclusions: Our data suggest that SHP-2 mutations in Noonan syndrome cause mild GH resistance by a postreceptor signaling defect, which seems to be partially compensated for by elevated GH secretion. This defect may contribute to the short stature phenotype in children with SHP-2 mutations and their relatively poor response to rhGH.

2002 ◽  
pp. 319-323 ◽  
Author(s):  
Y Rakover ◽  
A Silbergeld ◽  
I Lavi ◽  
R Masalha ◽  
IB Shlomo

OBJECTIVES: In the majority of children with short stature, the etiology is unknown. Mutations of the GH receptor (GHR) have been reported in a few children with apparent idiopathic short stature (ISS). These patients had low IGF-I, IGF-binding protein-3 (IGFBP-3) and GH-binding protein (GHBP), but a normal or exaggerated GH response to provocative stimuli, suggestive of partial GH insensitivity (GHI). We attempted to identify children with partial GHI syndrome, based on their response to GH provocative stimuli and other parameters of the GH-IGF-I axis. SUBJECTS AND METHODS: One hundred and sixty-four pre-pubertal children (97 boys, 67 girls) aged 7.2 (0.5-16.75) years were studied. All had short stature with height <3rd centile. The weight, bone age (BA) and body mass index (BMI) of the subjects, as well as the parents' heights and mid parental height (MPH) were assessed. Basal blood samples were taken for IGF-I, IGFBP-3 and GHBP. All subjects underwent a GH provocative test with either clonidine, arginine or insulin. The subjects were divided into three groups: (A) patients with peak GH concentration <18 mIU/l in two different provocative tests (GH deficiency - GHD, n=33); (B) patients with peak GH between 18.2 and 39.8 mIU/l (normal response, n=78); (C) patients with peak GH >40 mIU/l (exaggerated GH response, n=53). RESULTS: No significant differences were found in age, height (standard deviation score (SDS)), parental height (SDS) and the difference between chronological age and bone age (DeltaBA) between the groups. Patients with GHD were heavier (P=0.039) and had significantly higher BMI (SDS) (P=0.001) than the other groups. MPH (SDS) was lower in the group of exaggerated responders (P=0.04) compared with the other groups. No significant differences were found between the groups for the biochemical parameters when expressed nominally or in SDS, except for IGFBP-3 (SDS), which was lower in the GHD group (P=0.005). The GHBP levels were not lower in the group of exaggerated GH response to provocative stimuli. Height (SDS) correlated negatively with basal GH values in pooled data of all the subjects (r=-0.358, P<0.0001), in normal responders (r=-0.45, P<0.0001) and in the exaggerated responders (r=-0.341, P<0.0001), but not in the GHD group. CONCLUSION: Exaggerated GH response to provocative tests alone does not appear to be useful in identifying children with GHI.


2006 ◽  
Vol 154 (5) ◽  
pp. 659-666 ◽  
Author(s):  
S Pekic ◽  
M Doknic ◽  
D Miljic ◽  
M Joksimovic ◽  
J Glodic ◽  
...  

Objective: Posttreatment assessment of disease activity and definition of cure of acromegaly, using measurement of GH secretion, remains problematic. Furthermore, with our efforts to achieve tight biochemical control of the disease it is foreseeable that a proportion of patients may be rendered GH deficient, thus requiring testing for GH deficiency. The aim of our study was to evaluate residual GH secretion in cured patients with acromegaly. Design and methods: At baseline, circulating GH, IGF-I, IGFBP-3, leptin and lipid (cholesterol and tri-glycerides) levels were measured in 33 acromegalic patients nine years after treatment with surgery of whom 6 were additionally irradiated. Two tests were performed: the GH suppression test - oral glucose tolerance test (OGTT) and the GH provocation test - ghrelin test (1 μg/kg i.v. bolus) and the results were compared with 11 age- and sex-matched control subjects. Results: According to the consensus criteria (normal IGF-I levels and post-OGTT GH nadir <1 μg/l), 21 treated acromegalic patients were cured, 6 had discordant IGF-I and GH nadir values during OGTT, while 6 had persistent acromegaly. After the GH provocative test with ghrelin (cut-off for severe GH deficiency is GH <3 μg/l), we detected 9 severely GH deficient patients (GHD) among 21 cured acromegalic patients. Mean GH peak (±s.e.m.) response to the ghrelin test in GHD acromegalics was significantly lower compared with acromegalics with sufficient GH secretory capacity and control subjects (1.2 ± 0.2 μg/l vs 20.1 ± 2.4 μg/l vs 31.1 ± 2.5 μg/l respectively, P<0.0001). Mean IGF-I and IGFBP-3 levels were not different between GHD and GH-sufficient cured acromegalics. Leptin levels and body mass index (BMI) were significantly higher in GHD male acromegalics compared with GH-sufficient male acromegalics. GHD female acromegalics tended to have higher BMIs while leptin levels were not different. Conclusions: The assessment of residual GH secretory capacity by the GH provocation test is necessary in the long-term follow-up of successfully treated acromegalics since a large proportion of these patients are rendered GH deficient.


2020 ◽  
Vol 182 (3) ◽  
pp. 363-374 ◽  
Author(s):  
Masanobu Fujimoto ◽  
Jane C Khoury ◽  
Philip R Khoury ◽  
Bhanu Kalra ◽  
Ajay Kumar ◽  
...  

Objective Pregnancy-associated plasma protein-A2 (PAPP-A2) is a metalloproteinase that cleaves IGFBP-3 and IGFBP-5. Human mutations in PAPPA2 result in short stature with a low percentage of free IGF-I. Little is known about PAPP-A2 levels and the regulation of free IGF-I throughout childhood. We examined PAPP-A2 and intact IGFBP-3 levels in childhood and explored associations between PAPP-A2, free and total IGF-I, and total and intact IGFBP-3 and their relationship to the percentage of free to total IGF-I and anthropometric factors. Design Cross-sectional study at a single center. Methods PAPP-A2, free IGF-I, and intact IGFBP-3 levels were measured in childhood (3–18 years old) and an evaluation of the relationship between these proteins and anthropometric factors. Results In 838 children, PAPP-A2 consistently decreased throughout childhood. In contrast, free IGF-I increased. A pubertal peak in free IGF-I was present in females but was less evident in males. Intact and total IGFBP-3 increased throughout childhood; however, intact IGFBP-3 had a more marked rise than total IGFBP-3. Percent free IGF-I decreased with no distinct pubertal peak. PAPP-A2 levels positively correlated with the percent free IGF-I (Male, Female; r = 0.18, 0.38; P < 0.001) and negatively with intact IGFBP-3 (Male, Female; r = −0.58, −0.65; P < 0.0001). Conclusions This is the first study to describe serum PAPP-A2 and intact IGFBP-3 in children between 3 and 18 years of age. Our correlative findings suggest that PAPP-A2 is an important regulator of the percent free IGF-I which can be a marker of perturbations in the GH/IGF-I axis.


2021 ◽  
Vol 185 (5) ◽  
pp. 629-635
Author(s):  
Aristeidis Giannakopoulos ◽  
Alexandra Efthymiadou ◽  
Dionisios Chrysis

Objective The diagnosis of growth hormone deficiency (GHD) in children is not always straightforward because insulin-like growth factor 1 (IGF-I) or GH stimulation tests may not be able to discriminate GHD from constitutional delay of growth and puberty (CDGP) or other causes of short stature. Design Boys and girls (n = 429, 0.7–16 years) who attended our department for short stature participated in this study. They were followed up for an average period of 9 years. At the end of follow-up after reaching the final height, a definitive diagnosis was assigned, and all the components of ternary complex (IGF-I, IGF-binding protein-3 (IGFBP-3), acid-labile subunit (ALS), and IGF-I/IGFBP-3 ratio) were evaluated as biomarkers for the respective diagnosis. Results All the components of the ternary complex were tightly correlated with each other and were positively related to age. IGF-I, IGFBP-3, ALS, and IGF-I/IGFBP-3 ratio differed significantly between GHD and normal groups. IGF-I and ALS levels were lower in GHD compared to children with familial short stature, while IGF-I and IGF-I/IGFBP-3 ratio was significantly lower in GHD compared to children with CDGP. IGF-I and IGF-I/IGFBP-3 receiver operating curve cutoff points were unable to discriminate between GHD and normal groups or between GHD and CDGP groups. Conclusion Despite the tight correlation among all the components of the ternary complex, each one shows a statistically significant diagnosis-dependent alteration. There is a superiority of IGF-I, ALS, and IGF-I/IGFBP-3 ratio in the distinction between GHD and CDGP or between GHD and normal groups but without usable discriminating power, making auxology as the primary criterion for establishing the diagnosis.


1998 ◽  
Vol 48 (6) ◽  
pp. 719-724 ◽  
Author(s):  
Andrew M. Cotterill ◽  
Cecilia Camacho‐Hübner ◽  
Philippe Duquesnoy ◽  
Martin O. Savage
Keyword(s):  
Igf I ◽  

2005 ◽  
Vol 90 (8) ◽  
pp. 4679-4687 ◽  
Author(s):  
Yuki Kawashima ◽  
Susumu Kanzaki ◽  
Fan Yang ◽  
Tomoe Kinoshita ◽  
Keiichi Hanaki ◽  
...  

Context: Mouse knockout models have clearly demonstrated the critical importance of IGF-I and IGF receptor type 1 (IGF-IR) for embryonic growth as well as postnatal growth. Objective: We hypothesized that mutations of IGF-IR gene might predispose to short stature in children born with intrauterine growth retardation (IUGR). Patients: Twenty-four children with unexplained IUGR (birth weight &lt; −1.5 sd) and short stature (&lt;−2.0 sd) were screened for abnormalities of the IGF-IR gene. Methods: Direct DNA sequencing was used to identify IGF-IR gene mutations. Unprocessed IGF-IR proreceptor in fibroblasts was detected by immunoblot analysis. Functions of mutated IGF-IR in fibroblasts were evaluated by IGF-I binding, and IGF-I-stimulated DNA synthesis and β-subunit autophosphorylation. Results: We found the following results: 1) a heterozygous mutation (R709Q) changing the cleavage site from Arg-Lys-Arg-Arg to Arg-Lys-Gln-Arg was identified in a 6-yr-old Japanese girl (case 1) and her mother who also had IUGR with short stature (case 2); 2) fibroblasts from case 2 contained more IGF-IR proreceptor protein (189 ± 26% of normal) and less mature β-subunit protein (63 ± 12%); 3) [125I]IGF-I binding to fibroblasts from case 2 was reduced, compared with normal control (0.61 ± 0.16 × 106vs. 1.14 ± 0.12 × 106 sites per cell; P &lt; 0.05); and 4) both IGF-I-stimulated [3H]thymidine incorporation and IGF-IR β-subunit autophosphorylation were low in fibroblasts from case 2, compared with those of control (P &lt; 0.05). Conclusions: These findings strongly suggest that this mutation leads to failure of processing of the IGF-IR proreceptor to mature IGF-IR and causes short stature and IUGR.


2008 ◽  
Vol 18 ◽  
pp. S12
Author(s):  
H.A. van Duyvenvoorde ◽  
P.A. van Setten ◽  
M-J.E. Walenkamp ◽  
J. van Doorn ◽  
J. Koenig ◽  
...  

1993 ◽  
Vol 129 (5) ◽  
pp. 399-408 ◽  
Author(s):  
Torben Laursen ◽  
Jens OL Jorgensen ◽  
Hans Ørskov ◽  
Jens Møller ◽  
Alan G Harris ◽  
...  

Animal studies have demonstrated that in addition to inhibiting growth hormone (GH) secretion octreotide inhibits in a direct manner hepatic or peripheral insulin-like growth factor I (IGF-I) generation. To test this hypothesis in humans we studied ten GH-deficient patients with frequent blood sampling during 38 h on two occasions. Regular GH therapy was discontinued 72 h prior to each study period. At the start of each study a subcutaneous (sc) injection of GH (3 IU/m2) was given (at 18.00 h). In a single-blinded crossover design, patients received a continuous sc infusion of either octerotide (200 μg/24 h) or placebo (saline). The pharmacokinetics of GH were similar on the two occasions. The area under the curve±sem of serum GH was 142.5±53.6 μg·l−1·h−1 (octreotide) and 144.8±41.8 μg·l−1·h−1 (placebo), (p=0.73); Cmax (μg/l) was 12.5±1.47 (octreotide) and 12.8±1.42 (placebo) (p=0.83), and Tmax (h) was 6.1±0.97 (octreotide) and 5.2±0.65 (placebo) (p=0.49). Growth hormone administration was associated with an increase in serum IGF-I (μg/l), which was identical during the two studies, from 85.3±19.4 to 174.25±30.3 for octreotide and from 97.0±26.4 to 158.8±28.2 for placebo. Mean IGF-I levels (μg/l) were 138.2±25.1 (octreotide) and 134.5±28.6 (placebo) (p=0.78). Similarly, the increase in IGF binding protein 3 (IGFBP-3) levels was identical. Mean IGFBP-3 levels (μg/l) were 2303±323 (octreotide) and 2200±361 (placebo) (p=0.25). Mean insulin levels were significantly lower during octreotide treatment (39.9±17.9 mU/l) than during placebo (59.7±17.8 mU/l) (p<0.05). Mean blood glucose levels were elevated significantly during octreotide infusion (5.98±0.23 mmol/l for octreotide and 5.07±0.16 mmol/l for placebo; p=0.001). Glucagon levels decreased non-significantly (p=0.07) and IGFBP-1 levels tended to increase during infusion of octreotide although not significantly (p=0.41). Levels of the lipid intermediates were identical on the two occasions. Alanine and lactate levels were significantly increased during octreotide infusion. Mean levels of blood alanine (μmol/l) were 470.8±24.2 (octreotide) and 360.1±17.8 (placebo) (p<0.02). Mean levels of blood lactate were 1038±81.0 (octreotide) and 894.4±73.8 (placebo) (p<0.04). We conclude that short-term continuous sc infusion of octreotide has no direct effect on the generation of IGF-I or the pharmacokinetics of exogenous GH in GH-deficient man.


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