Genetic analysis in nine unrelated Italian patients affected by OTC deficiency: detection of novel mutations in the OTC gene
Genetic analysis in nine unrelated Italian patients affected by OTC deficiency: detection of novel mutations in the OTC gene
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DOI：
10.1016/s1096-7192(02)00028-8
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发表时间：
2002-06-01
影响因子：
3.8
通讯作者：
Zammarchi, E
中科院分区：
文献类型：
--
作者：
Bisanzi, S;Morrone, A;Zammarchi, E
鸟氨酸氨基转移酶缺乏症(OTCD)是一种X连锁的尿素循环障碍，是由于代谢酶鸟氨酸氨基转移酶(OTC)缺陷引起的。对9名受OTCD影响的无关意大利患者(1名男性患者和8名女性显性携带者)的基因分析导致检测到3种新的OTC基因突变和6种以前报道的OTC基因突变。对OTC基因、OTC外显子和内含子-外显子边界进行直接测序，并对患者外周血中提取的基因组DNA和总RNA进行限制性内切酶分析。在男性患者中，发现了由于核苷酸变化而产生的新突变S132P，该突变为C.394T>；C。在一个显性载体中，发现了导致新的氨基酸替代E98K的核苷酸突变C.292G>；A；该突变靠近OTC蛋白的氨基甲酰磷酸结合部位。在另一个显性载体中，OTC cDNA分析显示正常剪接的转录本和插入两个核苷酸的异常转录本(C.77-78insAG)。在患者的基因组DNA中，我们发现了一个处于杂合状态的新的横向IVS1-3C>；G；这种核苷酸变化在内含子I中产生了一个新的剪接受体位点，导致了RNA剪接缺陷。这种插入会导致OTC cDNAORF的框架移位，并导致过早终止密码子。在其他6名显性携带者中发现了上述突变N161S、R141Q、T178M、R92X、A208T、M268T。(C)2002年埃尔塞维尔科学公司(美国)。版权所有。
Ornithine transcarbamylase deficiency (OTCD) is an X-linked urea cycle disorder due to a defect of the mithocondrial enzyme ornithine transcarbamylase (OTC). Genetic analysis in nine unrelated Italian patients affected by OTCD (one male patient and eight female manifesting carriers) led to the detection of three novel mutations and six previously reported mutations in the OTC gene. The analysis was performed by direct sequencing of OTC cDNA, OTC exons, and intron-exon boundaries and enzymatic restriction analysis on the patients' genomic DNA and total RNA isolated from peripheral blood lymphocytes. In the male patient the new mutation S132P due to the nucleotide change c.394T>C was identified. In a manifesting carrier the nucleotide change c.292G>A that leads to the novel amino acid substitution E98K was identified; this mutation is close to the OTC protein's carbamyl phospate binding site. In another manifesting carrier the OTC cDNA analysis revealed the normally spliced transcript and an aberrant transcript with an insertion of two nucleotides (c.77-78insAG). In the patient's genomic DNA we identified a new transvertion IVS1-3C>G at the heterozygous state; this nucleotide change generates a new splice acceptor site in intron I that induces an RNA splicing defect. This insertion causes a frame shift in OTC cDNA ORF and leads to a premature stop codon. The previously described mutations N161S, R141Q, T178M, R92X, A208T, M268T were identified in the other six manifesting carriers. (C) 2002 Elsevier Science (USA). All rights reserved.