A Deep Intronic Mutation in the SLC12A3 Gene Leads to Gitelman Syndrome
A Deep Intronic Mutation in the SLC12A3 Gene Leads to Gitelman Syndrome
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DOI：
10.1203/pdr.0b013e3181b9b4d3
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发表时间：
2009-11-01
影响因子：
3.6
通讯作者：
Matsuo, Masafumi
中科院分区：
文献类型：
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作者：
Nozu, Kandai;Iijima, Kazumoto;Matsuo, Masafumi
在Gitelman综合征（GS，OMIM 263800）患者的SLC 12 A3基因中检测到许多突变。在以前的研究中，只有一个突变等位基因被检测到类似的20至41%的患者与GS;然而，未确定的确切原因尚未确定。在这项研究中，我们使用RT-PCR使用mRNA的第一次调查转录异常引起的深内含子突变。白细胞DNA的直接测序分析鉴定了外显子6中的一个碱基插入（c.818_819insG），但在另一个等位基因中未检测到突变。我们分析了从白细胞和尿沉渣中提取的RNA，检测到在外显子13和14之间含有238 bp的未知序列。内含子13的基因组DNA分析揭示了一个单碱基取代（c.1670- 191 C>T），其在内含子内产生了一个新的供体剪接位点，导致mRNA中包含一个新的隐蔽外显子。这是第一份报告创建一个剪接位点的深内含子单核苷酸的变化GS和第一份报告，以检测发病机制的患者GS和缺失突变的一个等位基因。这种分子发病机制可能部分解释了GS患者两个等位基因突变检测的成功率低。（儿科研究66：590- 593，2009）
Many mutations have been detected in the SLC12A3 gene of Gitelman syndrome (GS, OMIM 263800) patients. In previous studies, only one mutant allele was detected in similar to 20 to 41% of patients with GS; however, the exact reason for the nonidentification has not been established. In this study, we used RT-PCR using mRNA to investigate for the first time transcript abnormalities caused by deep intronic mutation. Direct sequencing analysis of leukocyte DNA identified one base insertion in exon 6 (c.818_819insG), but no mutation was detected in another allele. We analyzed RNA extracted from leukocytes and urine sediments and detected unknown sequence containing 238bp between exons 13 and 14. The genomic DNA analysis of intron 13 revealed a single-base substitution (c.1670-191C>T) that creates a new donor splice site within the intron resulting in the inclusion of a novel cryptic exon in mRNA. This is the first report of creation of a splice site by a deep intronic single-nucleotide change in GS and the first report to detect the onset mechanism in a patient with GS and missing mutation in one allele. This molecular onset mechanism may partly explain the poor success rate of mutation detection in both alleles of patients with GS. (Pediatr Res 66: 590-593,2009)