A novel mutation of the Succinate Dehydrogenase B Gene in a Korean Family with Pheochromocytoma

Abstract

Pheochromocytoma is a tumor that originates from the adrenal cortex and sympathetic chains. Most pheochromocytomas are sporadic, whereas others occur as hereditary syndromes. Familial pheochromocytoma has been frequently found in association with various mutations in genes of the succinate dehydrogenase family. A 21-year-old Korean male presented with recurrent chest tightness, severe headache, and hypertension. He was diagnosed as pheochromocytoma based on a 24-hour urine test, abdominal computed tomography, and ¹³¹I-MIBG scintigraphy. Genomic DNA was extracted from the patient’s whole blood. Primers covering all the coding regions and flanking introns of succinate dehydrogenase (SDH) B, C and D genes were designed and synthesized, and a DNA sequence analysis was performed using the polymerase chain reaction. Direct sequencing of the SDHB gene revealed a deletion of nucleotide 757 (thymidine) in exon 7. This thymidine deletion caused a shift in the reading frame that created a downstream stop codon and a truncated product (p.Cys253ValfsX5). Although the patient had no family history of pheochromocytoma, his father had the same mutation. We report a novel SDHB gene mutation from a Korean family with pheochromocytoma. This is the first report of pheochromocytoma with a confirmed SDHB germline mutation in Korea.