PHOX2B and hereditary disease: Heterozygote polyalanine expansion mutations in the exon 3 of PHOX2B are responsible for the majority of cases of CCHS, a rare genetic disease that affect the autonomic nervous system and central CO2 chemoreflexes (Amiel et al., 2003; Di Lascio et al., 2020; Weese-Mayer et al., 2017).