Moser Dirk, Ekawardhani Savira, Kumsta Robert, Palmason Haukur, Bock Christoph, Athanassiadou Zoi, Lesch Klaus-Peter, Meyer Jobst
Department of Neurobehavioral Genetics, Institute of Psychobiology, University of Trier, Trier, Germany.
Neuropsychopharmacology. 2009 Jan;34(2):458-67. doi: 10.1038/npp.2008.77. Epub 2008 Jun 4.
The human potassium-chloride co-transporter 3 (KCC3, SLC12A6) is involved in cell proliferation and in electro-neutral movement of ions across the cell membrane. The gene (SLC12A6) is located on chromosome 15q14, a region that has previously shown linkage with bipolar disorder, schizophrenia, rolandic epilepsy, idiopathic generalized epilepsy, autism and attention deficit/hyperactivity disorder. Furthermore, recessively inherited mutations of SLC12A6 cause Andermann syndrome, characterized by agenesis of the corpus callosum, which is associated with peripheral neuropathy and psychoses. Recently, we have demonstrated the association of two G/A promoter polymorphisms of SLC12A6 with bipolar disorder in a case-control study, and familial segregation of the rare variants as well as a trend toward association with schizophrenia. To investigate functional consequences of these polymorphisms, lymphocyte DNA was extracted, bisulfite modified, and subsequently sequenced. To investigate SLC12A6 promoter activity, various promoter constructs were generated and analyzed by luciferase reporter gene assays. We provide evidence that the G- allele showed a significant reduction of reporter gene expression. In human lymphocytes, the allele harboring the rare upstream G nucleotide was found to be methylated at the adjacent C position, possibly accountable for tissue-specific reduction in gene expression in vivo. Here we demonstrate functionality of an SNP associated with psychiatric disease and our results may represent a functional link between genetic variation and an epigenetic modification.
人类氯化钾共转运体3（KCC3，SLC12A6）参与细胞增殖以及离子跨细胞膜的电中性转运。基因（SLC12A6）位于15号染色体的q14区域，该区域先前已显示与双相情感障碍、精神分裂症、罗兰多癫痫、特发性全身性癫痫、自闭症和注意力缺陷多动障碍存在连锁关系。此外，SLC12A6的隐性遗传突变会导致安德曼综合征，其特征为胼胝体发育不全，并伴有周围神经病变和精神病。最近，我们在一项病例对照研究中证明了SLC12A6的两个G/A启动子多态性与双相情感障碍的关联，以及罕见变异的家族分离现象和与精神分裂症的关联趋势。为了研究这些多态性的功能后果，提取了淋巴细胞DNA，进行亚硫酸氢盐修饰，随后进行测序。为了研究SLC12A6启动子活性，构建了各种启动子构建体并通过荧光素酶报告基因检测进行分析。我们提供的证据表明，G等位基因显示报告基因表达显著降低。在人类淋巴细胞中，发现含有罕见上游G核苷酸的等位基因在相邻的C位置发生了甲基化，这可能是体内基因表达出现组织特异性降低的原因。在此，我们证明了一个与精神疾病相关的单核苷酸多态性的功能，我们的结果可能代表了遗传变异与表观遗传修饰之间的功能联系。
