Abstract 568: Few Carney's Triad patients have mutations in two subunits of the succinate dehydrogenase enzyme (SDHB, SDHC)

Abstract

Abstract Carney's triad (CTr) is a non-hereditary condition, primarily seen in young women, characterized by gastrointestinal stromal tumors (GIST), extra-adrenal paragangliomas and pulmonary chondromas. Most CTr patients present with GIST and pulmonary chondroma (incomplete CTr). A marked decrease in the enzymatic activity of succinate dehydrogenase (SDH) has been detected in these tumors, but the presence or absence of SDH mutations in CTr is controversial. A related disease, known as Carney-Stratakis Syndrome (CSS), has no female predisposition and presents with extra-adrenal paragangliomas and GIST tumors, without pulmonary chondromas. In distinction to CTr, CSS is hereditary due to germline SDH mutations in the enzyme's subunits (SDHA, SDHB, SDHC and SDHD) with corresponding decreased SDH activity in associated tumors. We have investigated 64 patients with CTr for germline mutations and/or deletions in the SDH subunit genes; four patients were found to have germline mutations in SDHB or SDHC. All four patients had multifocal gastric GIST and pulmonary chondromas at diagnosis; two subsequently developed paragangliomas, confirmed by biopsy. One of the patients with CTr and a SDHB mutation had a nephew with the same mutation and a neuroblastoma, confirming a previously reported association of neuroblastoma with gist (JMG 2009; 46:215, and AJMG 2010; 152A: 1531). We conclude that few CTr patients maybe more correctly classified as having CSS; the genetic distinction of CTr from CSS needs further study. [S.A.B. and P.X. should be regarded as joint first authors.] Citation Format: Sosipatros A. Boikos, Paraskevi Xekouki, Fabio R. Faucz, Karel Pacak, Margarita Raygada, Karen Adams, Evan Szarek, Evan Ball, Su Young Kim, Elena Fumagalli, Lee J. Helman, J Aidan Carney, Constantine A. Stratakis. Few Carney's Triad patients have mutations in two subunits of the succinate dehydrogenase enzyme (SDHB, SDHC). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 568. doi:10.1158/1538-7445.AM2014-568