title: Inherited mutations in pheochromocytoma and paraganglioma: why all patients should be offered genetic testing.
abstract: BACKGROUND
  Pheochromocytomas (PCC) and paragangliomas (PGL) are neuroendocrine tumors that, although rare, are an important cause of secondary hypertension because of the high morbidity and mortality. PCC/PGL are still thought of as the "tumor of tens," with 10 % being hereditary; however, recent population based studies suggest that up to 32 % of patients have a germline mutation in one of the known common susceptibility genes (including NF1, VHL, RET, SDHB, SDHD, and SDHC). Despite this, most patients in the United States are not referred for clinical genetic testing by their physicians. We aimed to examine the mutation prevalence in a clinic-based population in the United States.
  
  
  METHODS
  We performed a retrospective chart review of 139 consecutive patients with PCC/PGL from the medical genetics clinic at the hospital of the University of Pennsylvania from January 2004 through February 2012.
  
  
  RESULTS
  We found a 41 % overall mutation detection rate. Twenty-six percent of the cohort had a mutation in the SDHB or SDHD genes. Of patients with at least one PGL tumor outside the adrenal gland, 53 % had an identified mutation.
  
  
  CONCLUSIONS
  Forty-one percent of the cohort had a heritable mutation. The most commonly mutated gene was SDHB, which carries the highest risk of malignancy. These data, together with American Society of Clinical Oncology guidelines suggesting that genetic testing be performed if the risk of a hereditable mutation is at least 10 % or if it will affect medical management, strongly suggest that all patients with PCC/PGL should undergo clinical genetic testing.
authors.affiliation: Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: Fishbein
authors.forename: Shana
authors.initials: S
authors.lastname: Merrill
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Fraker
authors.forename: Debbie L
authors.initials: DL
authors.lastname: Cohen
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Nathanson
mesh_terms: D000008:Abdominal Neoplasms / Q000235:genetics; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000235:genetics*; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005820:Genetic Testing; D006258:Head and Neck Neoplasms / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D059645:Mutation Rate; D025542:Neurofibromin 1 / Q000235:genetics; D010236:Paraganglioma, Extra-Adrenal / Q000235:genetics*; D010386:Pelvic Neoplasms / Q000235:genetics; D010673:Pheochromocytoma / Q000235:genetics*; D017410:Practice Guidelines as Topic; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D012017:Referral and Consultation; D012189:Retrospective Studies; D013385:Succinate Dehydrogenase / Q000235:genetics; D013899:Thoracic Neoplasms / Q000235:genetics; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000235:genetics; D055815:Young Adult
chemical_list: D025542:Neurofibromin 1; C491545:SDHD protein, human; C108095:SDHB protein, human; D013385:Succinate Dehydrogenase; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human; C497446:VHL protein, human