FH and fumaric aciduria: Functional enzyme analysis in fibroblasts showed fumarate hydratase activity of 20% control level, and genetic analysis of the FH gene showed compound heterozygosity for mutations in c.844G>C p.Gly282Arg (present in the father) and c.1127A>C p.Gln376Pro (inherited from the mother), confirming a diagnosis of fumarate hydratase deficiency.