Normal visceral placement is driven by the dynein of nodal cilia, so patients with gene mutations encoding non-dynein structural components such as RSPH1 (Knowles et al., 2014), RSPH3 (Jeanson et al., 2015), and HYDIN (Olbrich et al., 2012) have not been reported for situs inversus. The gene discussed is HYDIN; the disease is situs inversus.