Tohoku J. Exp. Med., 2018 June, 245(2)

A Novel SDHB IVS2-2A>C Mutation Is Responsible for Hereditary Pheochromocytoma/Paraganglioma Syndrome

MIE YAMANAKA,^1,2 KIYOTO SHIGA,³ SHO FUJIWARA,¹ YASUHIKO MIZUGUCHI,¹ SARI YASUDA,^1,2 KOTA ISHIZAWA,¹ YURIKO SAIKI,¹ KENJIRO HIGASHI,^1,4 TAKENORI OGAWA,^1,4 NORIKO KIMURA⁵ and AKIRA HORII¹

¹Department of Molecular Pathology, Tohoku University School of Medicine, Sendai, Miyagi, Japan
²Exploring-Germination-and-Growth Program for Young Scientists, Tohoku University, Sendai, Miyagi, Japan
³Department of Otolaryngology and Head and Neck Surgery, Iwate Medical University School of Medicine, Morioka, Iwate, Japan
⁴Department of Otolaryngology-Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Miyagi, Japan
⁵Department of Clinical Research, Pathology Division, National Hospital Organization Hakodate National Hospital, Hakodate, Hokkaido, Japan

Pheochromocytomas and paragangliomas are neuroendocrine tumors which arise from adrenal medulla, and sympathetic or parasympathetic nerves, respectively. Hereditary cases afflicted by both or either pheochromocytomas and paragangliomas have been reported: these are called hereditary pheochromocytoma/paraganglioma syndromes (HPPS). Many cases of HPPS are caused by mutations of one of the succinate dehydrogenase (SDH) genes; mainly SDHB and SDHD that encode subunits for the mitochondrial respiratory chain complex II. In this study, we investigated mutations of SDH genes in six HPPS patients from four Japanese pedigrees using peripheral blood lymphocytes (from one patient with pheochromocytoma and five patients with neck paraganglioma) and tumor tissues (from two patients with paraganglioma). Results showed that all of these pedigrees harbor germline mutations in one of the SDH genes. In two pedigrees, a novel IVS2-2A>C mutation in SDHB, at the acceptor-site in intron 2, was found, and the tumor RNA of the patient clearly showed frameshift caused by exon skipping. Each of the remaining two pedigrees harbors a reported missense mutation, R242H in SDHB or G106D in SDHD. Importantly, all these mutations are heterozygous in constitutional DNAs, and two-hit mutations were evident in tumor DNAs. We thus conclude that the newly identified IVS2-2A>C mutation in SDHB is responsible for HPPS. The novel mutation revealed by our study may contribute to improvement of clinical management for patients with HPPS.

keywords —— germline mutation, hereditary pheochromocytoma/paraganglioma syndromes (HPPS), paraganglioma, pheochromocytoma, succinate dehydrogenase

© 2018 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2018, 245, 99-105

Correspondence: Akira Horii, M.D., Ph.D., Department of Molecular Pathology, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.

e-mail: horii@med.tohoku.ac.jp