GH-dependent IGF-I and IGFBP-3 secretion is not affected by heterozygosity for the E180 splice mutation that causes GHRD/Laron syndrome in the Ecuadorian population.
Classic Laron Syndrome (LS) is a recessive disease of insulin-like growth factor I (IGF-I) deficiency and primary growth hormone insensitivity, clinically characterized by dwarfism and marked obesity.
Laron syndrome (LS) is a genetic type of dwarfism that results from mutation of the growth hormone receptor (<i>GHR</i>) gene, and is the best characterized entity under the spectrum of the congenital IGF1 deficiencies.
Clinical and laboratory investigations starting in 1958 of a group of dwarfed children resembling isolated GH deficiency but who had very high serum levels of GH led to the description of the syndrome of primary GH resistance or insensitivity (Laron syndrome) and subsequently to the discovery of its molecular defects residing in the GH receptor and leading to an inability of IGF-I generation.
Serum profiles of insulin-like growth factors and their binding proteins in adults with growth hormone receptor deficiency treated with insulin-like growth factor I.
Growth hormone insensitivity syndrome (GHIS) of genetic origin is associated with many different mutations of the growth hormone receptor (GHR) gene and a recently described genetic defect of the insulin-like growth factor I (IGF-I) gene.
We studied 11 untreated adult patients with LS (5M, 6F), five girls with LS treated by IGF-I and five adult patients with GH gene deletion (3M, 3F), four previously treated by hGH in childhood.
There are currently four known genetic causes of GH insensitivity/primary IGF deficiency: GH receptor deficiency (also known as Laron syndrome or GH insensitivity syndrome), IGF-1 deficiency, signal transducer and activator of transcription 5b (STAT5b) deficiency and acid labile subunit (ALS) deficiency.
It combines with insulin-like growth factor-I (IGF-I) to form a complex (IGF-I/IGFBP-3) that can treat growth hormone insensitivity syndrome (GHIS) and reduce insulin requirement in patients with diabetes.
Insulin-like growth factor-I and insulin-like growth factor binding protein-3 cotreatment versus insulin-like growth factor-I alone in two brothers with growth hormone insensitivity syndrome: effects on insulin sensitivity, body composition and linear growth.
Conclusions Sequential measurements of serum IGF-I, glucose and potassium in patients with Laron syndrome may aid in optimizing and individualizing rhIGF-I treatment.
Clinical investigations started in 1958 of a group of children with characteristics resembling GH deficiency, but who had extremely high levels of plasma GH, led to the description of the syndrome of primary GH resistance or insensitivity (Laron syndrome), the discovery of its molecular defect, and the clinical application of biosynthetic insulin-like growth factor-I.
These findings are consistent with clinical data showing that IGF-I replacement therapy in patients with Laron syndrome does not achieve full skeletal growth.
As all patients with LS are IGF-I-deficient, it must be assumed that other as yet unknown factors related to the molecular defects in the GH-R are the major cause of the differences in intellect and brain abnormalities.
Recombinant human IGF-I is an effective treatment of severe primary IGF deficiency, which is typical of patients with GH receptor defects (Laron syndrome).
Most of the syndromes respond well to therapy with recombinant GH; exceptions are antibody-mediated resistance in GHD type IA (not all patients) and cases of Laron syndrome (GHR deficiency).Such patients respond to IGF-I therapy.
To identify IGF1-dependent genes and signaling pathways associated with cancer protection in LS, we conducted a genome-wide analysis using immortalized lymphoblastoid cells derived from LS patients and healthy controls of the same gender, age range, and ethnic origin.