FH and hereditary leiomyomatosis and renal cell cancer: Clinically, patients with germline biallelic loss of FH expression may present a range of symptoms, including developmental delay, hypotonia, and seizures in severe cases, while in the context of HLRCC (heterozygous germline mutation), patients may present with cutaneous and uterine leiomyomas, as well as renal cell carcinoma.