FLVCR2 and Fowler syndrome: Indeed, mutations in genes involved in heme biosynthesis are responsible for neuropathic Porphyrias and Friederich Ataxia; mutations in the heme importer FLVCR2 have been found in Fowler Syndrome; mutations in the heme exporter FLVCR1 cause Posterior Column Ataxia and Retinitis Pigmentosa, non-syndromic Retinitis Pigmentosa and Hereditary Sensory and Autonomic Neuropathies (Figure 1).