European Journal of Endocrinology (2012) 166 551–560 ISSN 0804-4643 CASE REPORT Functional characterization of a rare germline mutation in the gene encoding the cyclin-dependent kinase inhibitor p27Kip1 (CDKN1B) in a Spanish patient with multiple endocrine neoplasia-like phenotype Donatella Malanga1,2, Silvia De Gisi2, Miriam Riccardi1,2, Marianna Scrima2, Carmela De Marco1,2, Mercedes Robledo3 and Giuseppe Viglietto1,2 1Dipartimento di Medicina Sperimentale e Clinica ‘G Salvatore’, Universita` Magna Graecia, Campus Universitario Germaneto, 88100 Catanzaro, Italy, 2BIOGEM-Istituto di Ricerche Genetiche ‘G Salvatore’, 83031 Ariano Irpino (AV), Italy and 3Hereditary Endocrine Cancer Group, Human Cancer Genetics Programme, Spanish National Cancer Centre, Centro Nacional de Investigaciones Oncologicas (CNIO), Calle Melchor Fernandez Almagro 3, 28029 Madrid, Spain (Correspondence should be addressed to G Viglietto at Dipartimento di Medicina Sperimentale e Clinica ‘G Salvatore’ Universita` Magna Graecia; Email:
[email protected]) Abstract Objective: The aim of this study was to investigate the presence of germline mutations in the CDKN1B gene that encodes the cyclin-dependent kinase (Cdk) inhibitor p27 in multiple endocrine neoplasia 1 (MEN1)-like Spanish index patients. The CDKN1B gene has recently been identified as a tumor susceptibility gene for MEN4, with six germline mutations reported so far in patients with a MEN-like phenotype but negative for MEN1 mutations. Design and methods: Fifteen Spanish index cases with MEN-like symptoms were screened for mutations in the CDKN1B gene and the mutant variant was studied functionally by transcription/translation assays in vitro and in transiently transfected HeLa cells. Results: We report the identification of a heterozygous GAGA deletion in the 50-UTR of CDKN1B, NM_004064.3:c.-32_-29del, in a patient affected by gastric carcinoid tumor and hyperparathyroid- ism.