Table 3.

Summary of distinguishing features of whole xome sequencing, targeted next generation sequencing, and conventional Sanger sequencing in pheochromocytomas and paragangliomas

Feature	WES	Targeted NGS panel	Conventional testing (Sanger or MLPA)
Detection of known PPGL genes	Yesa	Yes	Yes
Need to process some PPGL exons separately (by conventional sequencing)	High	High	NA
Detection of novel genes	Yes	Nob	Nob
Detection of large genomic or copy number defects	Low	Yesb	Yesc
Fast turnaround time	Yes	Yes	Nod
Low costs	Yes	Yes	Noe
Complexity of bioinformatic analysis	High	Low	NA
Sequencing error rates	High	High	Low
Incidental findings	Yes	No	NA
VUS	High	High	Low
Performed in a stepwise manner	No	No	Yes
Individual lab autonomy for sequencing	No	Yes	Yes
Scalability	Lowf	High	NA

MLPA, multiplex ligation-dependent probe amplification, method used to detect copy number changes in PPGL genes; NA, not applicable; PPGL, pheochromocytomas and paragangliomas; VUS, variants of unknown significance; WES, whole-exome sequencing.

^aDetection of some PPGL gene exons may be incomplete in current platforms.

^bNew assay design required or use of a broad targeted panel.

^cBy MLPA assay.

^dException when first clinically driven test identifies mutated gene.

^eHigh costs if multistep gene analysis is required.

^fIncrease in WES scale can only occur at the expense of reduced sequencing depth per sample – not recommended.