Molecular Genetic Studies on Hereditary Orotic Aciduria

从人红细胞中提取了一种单磷酸脱羧酶(ODC)，经纯化后具有54000倍的比活力。编码该酶的cDNA克隆是从人胎盘cDNA文库中分离得到的。序列研究表明，人OPRT结构域和ODC结构域共存于同一开放阅读框架中。然后对遗传性口腔性酸尿症患者尿苷单磷酸合成酶(UMPS)基因进行分析，发现UMPS基因中同时含有OPRT和ODC基因。Northern印迹杂交结果显示，患者组和正常对照组之间的基因表达无明显差异。但在两者的连接部分检测到1个点突变。

Orotidine monophosphate decarboxylase (ODC) was extracted from human erythrocytes and was purified to have the specific activity of 54,000 folds. cDNA clone encoding this enzyme was isolated from human placenta cDNA library. Sequential studies revealed that human orotate phosphoribosyl transferase (OPRT) domain and ODC domain coexisted in the same open reading frame. Then, mutant uridine monophosphate synthetase (UMPS) cDNA, which contained both cDNA of OPRT and ODC, from the patient with hereditary orotic aciduria was analyzed. No difference of mRNA was revealed between the patient and normal controls by means of northern blot. But one point mutation was detected at the connecting part of the both cDNA.