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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Mutational analysis of the necdin gene in patients with congenital isolated hypogonadotropic hypogonadism

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Author(s):
Beneduzzi, Daiane [1] ; Iyer, Anita K. [2] ; Trarbach, Ericka Barbosa [1] ; Silveira-Neto, Acacio P. [1] ; Silveira, Leticia G. [1] ; Tusset, Cintia [1] ; Yip, Kathleen [2] ; Mendonca, Berenice B. [1] ; Mellon, Pamela L. [2] ; Latronico, Ana Claudia [1]
Total Authors: 10
Affiliation:
[1] Univ Sao Paulo, Lab Hormonios & Genet Mol LIM42, Fac Med, Unidade Endocrinol Desenvolvimento, Hosp Clin, BR-05403900 Sao Paulo - Brazil
[2] Univ Calif San Diego, Dept Reprod Med, Ctr Reprod Sci & Med, San Diego, CA 92103 - USA
Total Affiliations: 2
Document type: Journal article
Source: EUROPEAN JOURNAL OF ENDOCRINOLOGY; v. 165, n. 1, p. 145-150, JUL 2011.
Web of Science Citations: 5
Abstract

Context: Necdin activates GNRH gene expression and is fundamental for the development, migration, and axonal extension of murine GNRH neurons. In humans, necdin plays a potential role in the hypogonadotropic hypogonadism phenotype in patients with Prader-Willi syndrome. Aim: To investigate necdin gene (NDN) variants in patients with isolated hypogonadotropic hypogonadism (IHH). Patients and methods: We studied 160 Brazilian patients with IHH, which includes 92 with Kallmann syndrome and 68 with normosmic IHH. Genomic DNA was extracted and the single NDN exon was amplified and sequenced. To measure GNRH transcriptional activity, luciferase reporter plasmids containing GNRH regulatory regions were transiently transfected into GT1-7 cells in the presence and absence of overexpressed wild-type or mutant necdin. Results: A heterozygous variant of necdin, p.V318A, was identified in a 23-year-old male with Kallmann syndrome. The p.V318A was also present in affected aunt and his father and was absent in 100 Brazilian control subjects. Previous FGFR1 gene analysis revealed a missense mutation (p.P366L) in this family. Functional studies revealed a minor difference in the activation of GNRH transcription by mutant protein compared with wild type in that a significant impairment of the necdin protein activity threshold was observed. Conclusion: A rare variant of necdin (p.V318A) was described in a family with Kallmann syndrome associated with a FGFR1 mutation. Familial segregation and in vitro analysis suggested that this non-synonymous variant did not have a direct causative role in the hypogonadism phenotype. NDN mutations are not a frequent cause of congenital IHH. (AU)