GCDH and glutaryl-CoA dehydrogenase deficiency: For instance, two siblings with clinical and biochemical features of glutaric aciduria type I were homozygous for a familial missense VUS mutation, c.349G>A (p.Gly117Arg) in the GCDH gene, that was considered possibly linked to the disease as both parents were found heterozygote carriers for this mutation.