Succinate dehydrogenase variants in paraganglioma: why are B subunit variants 'bad'?

ABSTRACT: Mutations that predispose to familial pheochromocytoma and paraganglioma include inherited variants in the four genes (SDHA, SDHB, SDHC and SDHD) encoding subunits of succinate dehydrogenase (SDH), an enzyme of the mitochondrial tricarboxylic acid cycle and complex II of the electron transport chain. In heterozygous variant carriers, somatic loss of heterozygosity is thought to result in tumorigenic accumulation of succinate and reactive oxygen species. Inexplicably, variants affecting the SDHB subunit predict worse clinical outcomes. Why? Here we consider two hypotheses. First, relative to SDH A, C and D subunits, the small SDHB subunit might be more intrinsically 'fragile' to missense mutations because of its relatively large fraction of amino acids contacting

SUBMITTER: Gruber LM 

PROVIDER: S-EPMC10305465 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature