目的探讨采用分子遗传学检查诊断Crigler-Najjar综合征Ⅱ型的方法。方法在本科收治的3例高间接胆红素血症患者,抽取外周静脉血,提取基因组DNA,应用PCR法扩增尿苷二磷酸葡萄糖醛酸转移酶1A1基因(UGT1A1)所含5个外显子及其侧翼序列,进行DNA直接测序。结果 3例患者均检出UGT1A1基因5号外显子存在c.1456 T>G(p.Y486D)纯合突变;Y486D位于第5外显子上,使1456位胸腺嘧啶(T)突变为鸟嘌呤(G),导致486位氨基酸由酪氨酸(Tyr)变为天冬氨酸(Asp)。结论当临床上高度怀疑Crigler-Najjar综合征Ⅱ型时,应尽早行分子遗传学检查,确定其基因突变位点,以明确诊断。 Objective To explore the method of molecular diagnosis of Crigler-Najjar syndrome type Ⅱ. Methods Three patients with high indirect hyperbilirubinemia admitted to our hospital were enrolled in this study. Peripheral venous blood was extracted and genomic DNA was extracted. The five exons of UGT1A1 gene of uridine diphosphate glucuronyl transferase 1A (UGT1A1) Son and their flanking sequences for direct DNA sequencing. Results There was a homozygous mutation of c.1456 T> G (p.Y486D) in exon 5 of UGT1A1 gene in all three cases. Y486D was located on exon 5 and the 1456 thymine (T) was mutated to guanine (G), resulting in a 486 amino acid change from tyrosine (Tyr) to aspartic acid (Asp). Conclusion When the clinical suspicion of Crigler-Najjar syndrome type Ⅱ, molecular genetic tests should be performed as early as possible to determine the gene mutation sites in order to confirm the diagnosis.