Different Fumarate Hydratase Gene Variants Are Associated With Distinct Cancer Phenotypes

PURPOSE Whether individuals with monoallelicFHpathogenic variants (PVs) associated with autosomal recessive fumarate hydratase (FH) deficiency are also at risk of autosomal dominantFH-associated tumors is of paramount clinical importance. METHODS A retrospective study of individuals with a PV in theFHgene identified via multigene panel testing from 2012 to 2019 through a single testing laboratory was performed. Cancer histories of individuals with PVs inFH(FHPV) were compared to those with PVs associated only with autosomal recessive FH deficiency (FH-d PV) and toFH-negative controls. Cancer histories of individuals with truncating versus nontruncatingFHPV were also compared. RESULTS Individuals withFHPV were more likely to have kidney cancer than those with FH-d PV (odds ratio, 9.0; 95% CI, 4.4 to 20.0;P< .001) or FH-negative controls (odds ratio, 7.6; 95% CI, 5.2 to 11.2;Pvalue < .001). TheFHPV cohort had kidney cancer at a significantly younger age (median age: 35.0 years; interquartile range, 26.0-45.0 years) than the FH-d PV cohort (median age: 44.5 years; interquartile range, 43.5-53.5 years;P= .011). Within theFHPV cohort, there were no differences in the frequency or age at kidney cancer between those with truncating versus nontruncating PV. CONCLUSION UnlikeFHPV, FH-d PV are not associated with kidney cancers at early ages of onset. The FH-d PV cohort had a cancer phenotype that resembledFH-negative controls. These data may inform genetic counseling and risk assessment of individuals with FH-d PV.