Familial dysautonomia (FD; MIM223900) is an autosomal recessive congenital neuropathy that is caused by an intronic mutation in the IKBKAP gene, which encodes the inhibitor of κB kinase complex-associated protein (IKAP), also called elongator complex protein 1 (ELP1) (Anderson et al., 2001; Dong et al., 2002; Riley et al., 1949; Slaugenhaupt et al., 2001). The gene discussed is ELP1; the disease is Riley-Day syndrome.