Molecular Analysis of the Glyoxylate Reductase (GRHPR) Gene and Description of Mutations Underlying Primary Hyperoxaluria Type 2
Molecular Analysis of the Glyoxylate Reductase (GRHPR) Gene and Description of Mutations Underlying Primary Hyperoxaluria Type 2
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DOI：
10.1002/humu.9200
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发表时间：
2003-12-01
期刊：
影响因子：
3.9
通讯作者：
Rumsby, Gill
中科院分区：
文献类型：
--
作者：
Cregeen, David P.;Williams, Emma L.;Rumsby, Gill
原发性高尿酸2型是一种内源性草酸盐过量的常染色体隐性遗传病，由编码乙醛酸/羟基丙酮酸还原酶的GRHPR基因突变引起。采用PCR-SSCP结合基因组和cDNA序列分析的方法，对19例PH 2患者的GRHPR基因进行了突变分析。发现了11个突变，其中7个是新的。突变包括五个点突变：c.84-2A>G、c.295C>T（R99 X）、c.494G>A（G165 D）和c.904C>T（R302 C）以及六个微小缺失：c.103delG、c.375delG、c.403_405+2 delAAGT、c.540delT、c.608_609delCT和内含子1中更复杂的突变：c.84-13_c.84-12del; c.84-8_c.84-5del.由于c.403_405+2 delAAGT和c.84-2A>G突变，在肝mRNA中证实了异常转录物。此外，一个剪接变异体缺乏28 bp的外显子1中表达的一些组织，但未知的功能。在外显子6和内含子8分别发现了c.579A>G和a（CT）（n）微卫星多态性。表达研究表明，G165 D和R302 C突变体的乙醛酸还原酶活性分别为野生型蛋白的1.5%和5.6%。两种突变蛋白在纯化时都不稳定。尽管北方印迹分析表明GRHPR mRNA广泛表达，我们的研究表明GRHPR蛋白主要分布在肝脏，并得出结论，PH 2，像相关的1型疾病，主要是一种影响肝脏乙醛酸代谢的疾病。(C)2003 Wiley-Liss，Inc.
Primary hyperoxaluria type 2, an inherited autosomal recessive disorder of endogenous oxalate overproduction, is caused by mutations in the GRHPR gene encoding the glyoxylate/hydroxypyruvate reductase enzyme. The GRHPR genes from nineteen unrelated patients with PH2 were analysed for mutations using a combination of PCR-SSCP and sequence analysis of genomic and cDNA. Eleven mutations were identified, seven of which are novel. The mutations included five point mutations: c.84-2A>G, c.295C>T (R99X), c.494G>A (G165D), and c.904C>T (R302C) as well as six minor deletions: c.103delG, c.375delG, c.403_405+2 delAAGT, c.540delT, c.608_609delCT and a more complex mutation in intron 1: c.84-13_c.84-12del; c.84-8_c.84-5del. Aberrant transcripts were demonstrated in hepatic mRNA as a result of the c.403_405+2 delAAGT and c.84-2A>G mutations. In addition, a splice variant lacking 28 bp of exon 1 was expressed in a number of tissues but is of unknown function. Two polymorphisms, c.579A>G in exon 6 and a (CT)(n) microsatellite in intron 8 were identified. Expression studies showed that the G165D and R302C mutants had glyoxylate reductase activity 1.5 and 5.6% respectively of the wild type protein. Both mutant proteins were unstable on purification. Although there is wide expression of the GRHPR mRNA demonstrated by northern blot analysis, our study shows that GRHPR protein distribution is predominantly hepatic and concludes that PH2, like the related type 1 disease, is primarily a disorder affecting hepatic glyoxylate metabolism. (C) 2003 Wiley-Liss, Inc.