Familial dysautonomia (FD; also called Riley–Day syndrome) is a fatal autosomal recessive neurodegenerative disorder that is caused by an intronic mutation in IKBKAP/Elp1, the gene for inhibitor of kappa B kinase complex-associated protein (IKAP) (Riley et al., 1949; Anderson et al., 2001; Slaugenhaupt et al., 2001). The gene discussed is ELP1; the disease is Fabry disease.