Rare germline mutations identified by targeted next-generation sequencing of susceptibility genes in pheochromocytoma and paraganglioma.
BACKGROUND
Pheochromocytomas and paragangliomas have a highly diverse genetic background, with a third of the cases carrying a germline mutation in 1 of 14 identified genes.


OBJECTIVE
This study aimed to evaluate next-generation sequencing for more efficient genetic testing of pheochromocytoma and paraganglioma and to establish germline and somatic mutation frequencies for all known susceptibility genes.


METHODS
A targeted next-generation sequencing approach on an Illumina MiSeq instrument was used for a mutation analysis in 86 unselected pheochromocytoma and paraganglioma tumor samples. The study included the genes EGLN1, EPAS1, KIF1Bβ, MAX, MEN1, NF1, RET, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and VHL. RESULTS were verified in tumor and constitutional DNA with Sanger sequencing.


RESULTS
In all cases with clinical syndromes or known germline mutations, a mutation was detected in the expected gene. Among 68 nonfamilial tumors, 32 mutations were identified in 28 of the samples (41%), including germline mutations in EGLN1, KIF1Bβ, SDHA, SDHB, and TMEM127 and somatic mutations in EPAS1, KIF1Bβ, MAX, NF1, RET, and VHL, including one double monoallelic EPAS1 mutation.


CONCLUSIONS
Targeted next-generation sequencing proved to be fast and cost effective for the genetic analysis of pheochromocytoma and paraganglioma. More than half of the tumors harbored mutations in the investigated genes. Notably, 7% of the apparently sporadic cases carried germline mutations, highlighting the importance of comprehensive genetic testing. KIF1Bβ, which previously has not been investigated in a large cohort, appears to be an equally important tumor suppressor as MAX and TMEM127 and could be considered for genetic testing of these patients.
Department of Clinical and Experimental Medicine (J.W., O.G., P.S.), Faculty of Health Sciences, Linköping University, Departments of Surgery (O.G.) and Clinical Genetics (P.S.), County Council of Östergötland, Linköping SE-58185, Sweden; Department of Oncology-Pathology (A.A., C.C.J., A.H., C.L.), Karolinska Institutet, Cancer Center Karolinska (A.A., C.C.J., A.H., C.L.), Karolinska University Hospital Solna, and Department of Molecular Medicine and Surgery (A.A., C.C.J., M.B., C.L.), Karolinska Institutet, Karolinska University Hospital, Stockholm SE-17176, Sweden; and Wisconsin National Primate Research Center (R.W.W.), University of Wisconsin-Madison, Madison, Wisconsin 53715.
Jenny
J
Welander
Adam
A
Andreasson
C Christofer
CC
Juhlin
Roger W
RW
Wiseman
Martin
M
Bäckdahl
Anders
A
Höög
Catharina
C
Larsson
Oliver
O
Gimm
Peter
P
Söderkvist
D000310:Adrenal Gland Neoplasms / Q000453:epidemiology / Q000235:genetics*; D000328:Adult; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005820:Genetic Testing; D018095:Germ-Line Mutation; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008297:Male; D008875:Middle Aged; D010235:Paraganglioma / Q000453:epidemiology / Q000235:genetics*; D010673:Pheochromocytoma / Q000453:epidemiology / Q000235:genetics*; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult