这个基因编码一个UDP葡萄糖醛酸基转移酶，一种葡萄糖醛酸化途径的酶，能将小的亲脂性分子，如类固醇、胆红素、激素和药物，转化为水溶性、可排泄的代谢物。这个基因是一个复杂基因座的一部分，编码几个UDP葡萄糖醛酸转移酶。该位点包括13个唯一的交替第一外显子，随后是4个常见外显子。四个交替的第一外显子被认为是假基因。其余9个5’外显子中的每一个都可以拼接到4个常见外显子上，从而产生9个具有不同N端和相同C端的蛋白质。每个第一外显子编码底物结合位点，并由其自身的启动子调控。这种酶的首选底物是胆红素，尽管它对简单的酚类、黄酮类和C18类固醇也有中等活性。该基因突变导致I型和II型Crigler-Najjar综合征和吉尔伯特综合征。
This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. The preferred substrate of this enzyme is bilirubin, although it also has moderate activity with simple phenols, flavones, and C18 steroids. Mutations in this gene result in Crigler-Najjar syndromes types I and II and in Gilbert syndrome.