Israel Medical Association Journal

Background: Treatment of patients with childhood growth hormone deficiency is usually terminated at the end of puberty. Follow-up into adult age is rare, even more so in patients with congenital isolated growth hormone deficiency (cIGHD).

Objectives: To assess the clinical and social characteristics of adults with cIGHD who received growth hormone (hGH) treatment in childhood.

Methods: Thirty-nine patients (23 men, 16 women) diagnosed in our clinic with cIGHD at 7 ± 4.2 years, and treated with hGH during childhood for 2–18 years, were followed into adulthood (mean age 30.7 ± 13.3 years). Ascertained detailed data were found for 32 patients.

Results: Mean ± SD height for males was 160.2 ± 10.6 cm and for females 146.4 ± 5.4 cm. All patients achieved full sexual development and 14 were married. After cessation of GH treatment and with advanced age all exhibited a progressive increase in adiposity to the degree of obesity. Twelve patients suffered from hyperlipidemia, 4 developed diabetes mellitus, and 5 have cardiovascular diseases. One patient died in an accident. None developed cancer. Of the 39 patients, 22 have an education level of high school or higher, and 2 are in special institutions. Most are employed in manual labor.

Conclusions: Patients with congenital IGHD who do not receive early and regular replacement treatment are prone to lag in achieving normal height and suffer from educational and vocational handicaps.

Background: Laron Syndrome, first described in Israel, is a form of dwarfism similar to isolated growth hormone deficiency caused by molecular defects in the GH[1] receptor gene.

Objective: To characterize the molecular defects of the GH-R[2] in Laron syndrome patients followed in our clinic.

Methods: Of the 63 patients in the cohort, we investigated 31 patients and 32 relatives belonging to several ethnic origins. Molecular analysis of the GH-R gene was performed using the single strand conformation polymorphism and DNA sequencing techniques.

Results: Eleven molecular defects including a novel mutation were found. Twenty-two patients carried mutations in the extracellular domain, one in the transmembrane domain, and 3 siblings with typical Laron syndrome presented a normal GH-R. Of interest are, on one hand, different mutations within the same ethnic groups: W-15X and 5, 6 exon deletion in Jewish-Iraqis, and E180 splice and 5, 6 exon deletion in Jewish-Moroccans; and on the other hand, identical findings in patients from distinct regions: the 785-1 G to T mutation in an Israeli-Druze and a Peruvian patient. A polymorphism in exon 6, Gly168Gly, was found in 15 probands. One typical Laron patient from Greece was heterozygous for R43X in exon 4 and heterozygous for Gly168Gly. In addition, a novel mutation in exon 5: substitution of T to G replacing tyrosine 86 for aspartic acid (Y86D) is described.

Conclusions: This study demonstrates: a) an increased focal incidence of Laron syndrome in different ethnic groups from our area with a high incidence of consanguinity; and b) a relationship between molecular defects of the GH-R, ethnic group and geographic area.

Ghrelin, a 28 amino acid acylated peptide predominantly produced by the stomach, displays strong growth hormone-releasing activity mediated by the hypothalamus-pituitary GH[1] secretagogue receptors that were found to be specific for a family of synthetic, orally active GH secretagogues. The discovery of ghrelin brings us to a new understanding of the regulation of GH secretion. However, ghrelin is much more than simply a natural GH secretagogue. It also acts on other central and peripheral receptors and exhibits other actions, including stimulation of lactotroph and corticotroph secretion, orexigenia, influences gastroenteropancreatic functions, and has metabolic, cardiovascular and anti-proliferative effects. Knowledge of the whole spectrum of biologic activities of this new hormone will provide new understanding of some critical aspects of neuroscience, metabolism and internal medicine. In fact, GHS[2] were born more than 20 years ago as synthetic molecules, eliciting the hope that orally active GHS could be used to treat GH deficiency as an alternative to recombinant human GH. However, the dream did not become reality and the usefulness of GHS as an anabolic anti-aging intervention restoring the GH/IGF-I[3] axis in somatopause is still unclear. Instead, we now face the theoretic possibility that GHS analogues acting as agonists or antagonists could become candidate drugs for the treatment of pathophysiologic conditions in internal medicine totally unrelated to disorders of GH secretion.