Table 3.

Clinical manifestations.

Phenotype	SDHB	SDHC	SDHD	References
Multiple primary tumors	Not commom	Not common	Common	Raygada et al. (1); Pasini and Stratakis (25)
Single primary tumors	Common	Common	Not common	Raygada et al. (1); Pasini and Stratakis (25)
Extra adrenal tumors	Common (50%–67%)	Less common	Less common (18%–21%)
HNPGL	Less common (27%–31%)	Common	Common (71%–89%)	Niemann et al. (8)
Risk for malignancy	High (34%–37%)	Low	Low (8%)	Bardella et al. (32); Benn et al. (33);

Note: Many studies are still analyzing data and associated risks may change as more cases are reported.