Novel inactivating mutations in the GH secretagogue receptor gene in patients with constitutional delay of growth and puberty

Author(s)

Pugliese-Pires, Patricia N. ^[1] ; Fortin, Jean-Philippe ^[2] ; Arthur, Thais ^[3] ; Latronico, Ana Claudia ^[1] ; Mendonca, Berenice B. ^[1] ; Villares, Sandra Mara F. ^[3] ; PArnhold, Ivo J. ^[1] ; Kopin, Alan S. ^[2] ; Jorge, Alexander A. L. ^{[1, 4]}

Affiliation

^[1] Univ Sao Paulo FMUSP, Fac Med, Disciplina Endocrinol, Lab Hormonios Genet Mol LIM 42, Unidad Endocrinol, BR-05403000 Sao Paulo - Brazil

^[2] Tufts Med Ctr, Mol Pharmacol Res Ctr, Mol Cardiol Res Inst, Boston, MA - USA

^[3] Univ Sao Paulo FMUSP, Fac Med, Hosp Clin, Lab Nutr Humana & Doencas Metabol LIM 25, BR-01246903 Sao Paulo - Brazil

^[4] Univ Sao Paulo FMUSP, Fac Med, Disciplina Endocrinol, Hosp Clin, Unidade Endocrinol Genet LIM 25, BR-01246903 Sao Paulo - Brazil

• Document type: Journal article
• Source: EUROPEAN JOURNAL OF ENDOCRINOLOGY; v. 165, n. 2, p. 233-241, AUG 2011.
• Web of Science Citations: 26

Abstract

Background: A limited number of mutations in the GH secretagogue receptor gene (GHSR) have been described in patients with short stature. Objective: To analyze GHSR in idiopathic short stature (ISS) children including a subgroup of constitutional delay of growth and puberty (CDGP) patients. Subjects and methods: The GHSR coding region was directly sequenced in 96 independent patients with ISS, 31 of them with CDGP, in 150 adults, and in 197 children with normal stature. The pharmacological consequences of GHSR non-synonymous variations were established using in vitro cell-based assays. Results: Five different heterozygous point variations in GHSR were identified (c.-6 G>C, c.251G>T (p.Ser84Ile), c.505G>A (p.Ala169Thr), c.545 T>C (p.Val182Ala), and c.1072G>A (p.Ala358Thr)), all in patients with CDGP. Neither these allelic variants nor any other mutations were found in 694 alleles from controls. Functional studies revealed that two of these variations (p.Ser84Ile and p. Val182Ala) result in a decrease in basal activity that was in part explained by a reduction in cell surface expression. The p.Ser84Ile mutation was also associated with a defect in ghrelin potency. These mutations were identified in two female patients with CDGP (at the age of 13 years, their height SDS were -2.4 and -2.3). Both patients had normal progression of puberty and reached normal adult height (height SDS of -0.7 and -1.4) without treatment. Conclusion: This is the first report of GHSR mutations in patients with CDGP. Our data raise the intriguing possibility that abnormalities in ghrelin receptor function may influence the phenotype of individuals with CDGP. (AU)

• FAPESP's process: 09/00313-3 - Study of growth hormone secretagogue receptor (GHSR) gene in children with isolated growth hormone deficiency and children with idiopatic short stature
• Grantee: Alexander Augusto de Lima Jorge
• Support Opportunities: Regular Research Grants