Exploiting natural variants in potassium channel genes to understand their roles in neural function, behaviour and development

基本原理和影响：大约有100个编码钾通道的基因，其中约40%与疾病相关，通常表现为发育迟缓、共济失调和癫痫。我们的目标是系统地评估剩余的钾通道基因的功能，以更好地了解这个基因家族。这种理解将产生影响，这些数据将有助于改善对具有这些基因致病变异的人的诊断和干预。我们最近发现了一种新的综合征，其特征是钾通道基因KCNC4的变异引起的共济失调和发育延迟。我们的创新方法结合了对人类变异的生物信息学研究、通道功能的分子建模以及在非洲爪哇模式生物中重现人类表型，以将基因与这种疾病联系起来，并了解其分子基础。我们将把这种成功的方法推广到其他钾通道。方法：生物信息学：来自100,000基因组计划(100KGP)和NHS基因组医学服务中罕见疾病患者的全基因组序列将被询问钾通道基因的破坏性变异。这些将根据生物信息学工具、先证者的数量及其表型来确定最有可能致病的基因。离子通道功能：使用成熟的电生理分析，将使用HEK细胞中的膜片钳相对于野生型通道来测量检测到的变体对离子通道功能的影响。这将确定变异是否影响通道功能，以及这种干扰的性质是什么。非洲爪哇模型：利用CRISPR在非洲爪哇中敲除有希望的基因，并对由此产生的形态、生理和行为变化进行系统评估。这将决定基因在整个有机体中的正常功能。条件素质：在现有的、成功的合作中参与多学科项目的能力。具体地说，对生物信息学、电生理学、分子遗传学和表型鉴定感兴趣。

Rationale and Impact: There are around 100 genes encoding potassium channels, and around 40% of these are associated with diseases, generally displaying developmental delay, ataxia and epilepsy.We aim to systematically assess the function of the remaining potassium channel genes to better understand this gene family. This understanding will have impact, the data will help improve diagnosis and interventions for people who have pathogenic variants in these genes.We recently identified a novel syndrome characterised by ataxia and developmental delay caused by variants in a potassium channel gene, KCNC4. Our innovative approach combined bioinformatics investigation of human variation, molecular modelling of channel function, and recapitulation of the human phenotype in the Xenopus model organism to link the gene to the disorder and understand its molecular basis. We will extend this successful approach to other potassium channels.Approach:Bioinformatics: Whole genome sequences from patients with rare disorders in the 100,000 Genomes Project (100KGP) and NHS Genomic Medicine Service will be interrogated for damaging variants in potassium channel genes. These will be prioritised based on bioinformatics tools, number of probands and their phenotypes to determine the most likely disease causing genes.Ion channel function: Using well established electrophysiological assays, the impact of the detected variants on ion channel function will be measured relative to the wild-type channel using patch clamp in HEK cells. This will establish whether the variants impact channel function, and what the nature of that disruption is.Xenopus models: Promising genes will be knocked-out using CRISPR in Xenopus, and the resultant morphological, physiological and behavioural changes systematically assessed. This will determine the normal function of the gene in the whole organism.Candidate qualities: An ability to engage with a multi-disciplinary project within an existing, successful collaboration. Specifically, an interest in bioinformatics, electrophysiology, molecular genetics and phenotyping.