Bertino F, Firestone K, Bellacchio E, et al. - In their previous work, researchers identified heme metabolism as a novel pathway contributing to sensory neurons maintenance and nociception and that the feline leukemia virus subgroup C receptor 1 (FLVCR1) gene exhibits mutations in individuals affected by hereditary sensory and autonomic neuropathies (HSANs) and that FLVCR1 gene encodes for 2 heme export proteins, FLVCR1a (plasma membrane) and FLVCR1b (mitochondria), crucially involved in the regulation of cellular heme homeostasis. They here report on two additional patients carrying novel biallelic mutations in FLVCR11 translation initiation codon (c.2T>C; p.(Met1Thr) and c.3G>T; p.(Met1Ile)). The c.2T>C; p.(Met1Thr) mutant was overexpressed in human cell lines and its impact on protein structure and function was delineated in comparison with other HSAN-related mutations. In the following 2 different ways, translation was influenced by the mutation: by reducing levels of translation of wild-type protein and it inducing translation initiation from a downstream in-frame ATG, leading to the production of an N-terminal truncated protein that is retained in the endoplasmic reticulum. They identified novel FLVCR1 mutations in HSAN that strengthens the crucial role of heme in sensory neuron maintenance and pain perception. Moreover, the in vitro findings illustrate that HSAN patients did not lose heme export completely, thus inferring the possibility to improve FLVCR1 expression/activity for therapeutic purposes.