Inheritance of a single variant FH allele predisposes the individual to develop manifestations of HLRCC, while inherited biallelic pathogenic variants cause fumarate hydratase deficiency (FHD) in autosomal recessive mode, a disorder characterized by neurological impairment and death in the first decade of life [28]. The gene discussed is FH; the disease is hereditary leiomyomatosis and renal cell cancer.