SDHB encodes a subunit of the succinate dehydrogenase (SDH) complex, a mitochondrial enzyme that converts succinate to fumarate in the citric acid cycle and transfers electrons to the oxidative phosphorylation pathway. It functions as a tumor suppressor, and loss of its function stabilizes hypoxia-inducible factors, promoting tumor development. Inherited mutations in SDHB cause hereditary paraganglioma and pheochromocytoma, and SDH dysfunction is also linked to gastrointestinal stromal tumors, renal cell carcinoma, and pituitary adenomas. Mutations in this gene are additionally associated with mitochondrial complex II deficiency.
This intronic deletion does not change the SDHB protein and is common in population databases, so it shows no clear link to the tumor-suppressor dysfunction that drives hereditary paraganglioma and pheochromocytoma. It remains a variant of uncertain significance.
No ACMG/AMP criteria were met; with no pathogenic or benign combination threshold satisfied, the variant is classified as a variant of uncertain significance (VUS).
No criteria were applied for this variant.
European (non-Finnish) 1138 / 1,166,716 |
0.098% 1 hom |
Remaining individuals 48 / 61,758 |
0.078% |
African/African American 25 / 74,054 |
0.034% |
Admixed American 19 / 59,052 |
0.032% |
European (Finnish) 9 / 60,780 |
0.015% |
South Asian 11 / 90,230 |
0.012% 1 hom |
Ashkenazi Jewish 2 / 29,290 |
0.0068% |
East Asian 1 / 44,506 |
0.0022% |
European (non-Finnish) 75 / 117,934 |
0.064% |
African/African American 8 / 22,994 |
0.035% |
Admixed American 9 / 33,024 |
0.027% |
Ashkenazi Jewish 2 / 9,804 |
0.02% |
Remaining individuals 1 / 6,676 |
0.015% |
European (Finnish) 3 / 20,620 |
0.015% |
South Asian 3 / 28,748 |
0.01% |
African/African American 1 / 1,020 |
0.098% |
European (non-Finnish) 7 / 11,740 |
0.06% |
