Table 1.

Clinical characteristics of carriers of pathogenic variants in succinate dehydrogenase subunits B and D (SDHB and SDHD).

Clinical Characteristics	SDHB n = 192	SDHD n = 232
Male (%)/female (%)	81 (42.2)/111 (57.8)	123 (53.0)/109 (47.0)
Mean age at genetic testing	46 years (range 9–77)	44 years (range 16–73)
HNPGL (%)	53 (27.6)	198 (85.3)
sPGL (%)	26 (13.5)	18 (7.8)
Pheochromocytoma (%)	4 (2.1)	16 (6.9)
Malignant PGL (%)	14 (7.3)	4 (1.7)
Unaffected (%)	110 (57.3)	30 (12.9)

HNPGL = head and neck paraganglioma, sPGL = sympathetic paraganglioma, PGL = paraganglioma.