SDH deficiency is very common in carotid body paragangliomas: Genetic counseling and testing should be offered to all patients.

BACKGROUND

Collectively, germline pathogenic variants in succinate dehydrogenase (SDH) genes are the most common cause of hereditary paragangliomas. Loss of immunohistochemical expression of SDHB protein (termed SDH deficiency) occurs whenever there is biallelic inactivation of any SDH gene. We sought to estimate the prevalence of SDH deficiency in patients with carotid body paragangliomas.

METHODS

We identified all carotid body paragangliomas that had undergone surgical excision at our institution over the last 30 years. If SDHB immunohistochemistry was not performed at the time of excision, it was performed on archived material.

RESULTS

There were 64 carotid body paragangliomas identified in the 62 patients. Two-thirds of the patients were female, and 43 (67%) were SDH-deficient.

CONCLUSION

Up to two-thirds of all carotid body paragangliomas are associated with SDH deficiency. Therefore, genetic testing and counseling should be offered to all patients with carotid body paragangliomas, regardless of age or family history.