Clinical Trial: Status of Growth Hormone/ Insulin-like Growth Factor-1 (GH/IGF-1) Axis and Growth Failure in Ataxia Telangiectasia (AT)

Study Status: Recruiting
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Status of the Growth Hormone/ Insulin-like Growth Factor-1 (GH/IGF-1) Axis in Relation to Growth Failure, Body Weight and Neuroprotection in Children With Ataxia Telangiectasia

Brief Summary: This study will evaluate the status of the growth hormone/ insulin-like growth factor-1 (GH/IGF-1) axis in relation to growth failure, body weight and composition and neuroprotection in children with Ataxia telangiectasia (AT).

Detailed Summary:

Growth failure and GH/IgF-1 deficiency has been described in patients diagnosed with Ataxia telangiectasia (AT) [Boder et al.,1958]. This condition is a fatal inherited disease caused by a mutation of the ATM gene on chromosome 11 leading to chromosomal instability, immunodeficiency, cancer susceptibility and and endocrinological abnormalities. In this regard, several groups demonstrated a cross-linking of ATM with growth factor pathways. Participation of the ATM protein in insulin signaling through phosphorylation of eIF-4E-binding protein 1 has been postulated [Yang et al.,2000]. Peretz et al.[2001] described that expression of the insulin-like growth factor-I receptor is (IGF-I R) ATM dependent in a pathway regulating radiation response. In addition, Shahrabani-Gargir et al.[2004] found that the ATM gene controls IGF-I R gene expression in a DNA damage response pathway. Suzuki et al.[2004] described that IGF-I phosphorylates AMPK-alpha, a key regulator of cholesterol and fatty acid synthesis, acts in an ATM-dependent manner . We have recently demonstrated reduced levels of circulating Insulin-like growth factor-I (IGF-I) and its main binding protein 3 (IGFBP-3) in AT patients accompanied with decreased body mass index [Schubert et al.,2005]. Furthermore, apart from regulating somatic growth and metabolism, evidence suggests that the GH/IGF-I axis is involved in the regulation of brain growth, development and myelination. Moreover, GH and particularly IGF-1 have potential neuroprotective effects in different in vitro and in vivo experimental models. In addition we have recently shown that extracerebellar MRI-lesions in AT go along with deficiency of the GH/IGF-1 Axis, markedly reduced body weight, high ataxia scores and advanced age [Kieslich et al.,2009]. Supplementation with these growth hormones might overcome the progressive dystrophy and may have clinical benefits against the progression of neurodegeneration and i
Sponsor: Johann Wolfgang Goethe University Hospital

Current Primary Outcome: To evaluate the GH increase after Arginine Provocation Test [ Time Frame: at minute 0, 30, 60, 90 und 120 after infusion ]

Original Primary Outcome: Same as current

Current Secondary Outcome: The GH increase after Clonidine Provocation Test. To evaluate the safety and efficacy of the IGF-1 generation test. To correlate GH/IgF-1 deficiency to BMI To correlate GH/IgF-1 deficiency to MRI findings [ Time Frame: at minute 0, 30, 60, 90 und 120 after dosing of Clonidin. IgF-1 generation test after 5 days. ]

Original Secondary Outcome: Same as current

Information By: Johann Wolfgang Goethe University Hospital

Dates:
Date Received: January 19, 2010
Date Started: January 2010
Date Completion: September 2012
Last Updated: July 2, 2010
Last Verified: July 2010