For example, patients with genetic hyperbilirubinemias such as Dubin-Johnson syndrome, a disorder involving mutations in the bilirubin transporter ABCC2, or Crigler-Najjar Type 1, a disorder involving mutations in the bilirubin glucuronosyltransferase UGT1A1, rarely complain of pruritus (Levitt and Levitt, 2014; van der Veere et al., 1996). This evidence concerns the gene UGT1A1 and Dubin-Johnson syndrome.