Stargardt黄斑营养不良(STGD1)是全球最常见的遗传性儿童失明形式,目前尚无治疗方法。它是由ABCA4突变引起的常染色体隐性遗传疾病。迄今为止,已经测试了多种基因补充方法来创建一种疗法,一些达到临床试验。新技术,例如基于CRISPR-Cas的编辑系统,通过允许致病性突变的靶向DNA或RNA碱基编辑,为解决遗传疾病提供了令人兴奋的前沿。ABCA4有1200个已知的致病突变,其中63%是适合这种编辑技术的过渡突变。在这份报告中,我们从gnomAD的可用数据中筛选了ABCA4中已知的“致病性”和“可能的致病性”突变,莱顿开放变异数据库(LOVD),和ClinVar有关相关基础编辑的潜在PAM站点,包括化脓性链球菌Cas(SpCas),金黄色葡萄球菌Cas(SaCas),和SaCas的KKH变体(Sa-KKH)。总的来说,筛选的突变,53%(ClinVar),71%(LOVD),和71%(gnomAD),是可编辑的,致病性过渡突变,其中35-47%拥有“理想”的PAM网站。在这些突变中,16-20%发生在多个PAM站点的范围内,启用各种编辑策略。Further,在来自德国的三个队列的相关患者数据中,丹麦,和中国,我们发现44-76%的病人,取决于复杂等位基因的存在,至少有一个与附近的SaCas的过渡突变,SpCas,或Sa-KKHPAM站点,这将允许潜在的DNA碱基编辑作为一种治疗策略。考虑到Stargardt遗传景观的复杂性,这些发现更清楚地了解了DNA碱基编辑方法作为ABCA4基因治疗策略的应用潜力.
Stargardt macular dystrophy (STGD1) is the most common form of inherited childhood blindness worldwide and for which no current treatments exist. It is an autosomal recessive disease caused by mutations in ABCA4. To date, a variety of gene supplementation approaches have been tested to create a therapy, with some reaching clinical trials. New technologies, such as CRISPR-Cas based editing systems, provide an exciting frontier for addressing genetic disease by allowing targeted DNA or RNA base editing of pathogenic mutations. ABCA4 has ∼1,200 known pathogenic mutations, of which ∼63% are transition mutations amenable to this editing technology. In this report, we screened the known \"pathogenic\" and \"likely pathogenic\" mutations in ABCA4 from available data in gnomAD, Leiden Open Variation Database (LOVD), and ClinVar for potential PAM sites of relevant base editors, including Streptococcus pyogenes Cas (SpCas), Staphylococcus aureus Cas (SaCas), and the KKH variant of SaCas (Sa-KKH). Overall, of the mutations screened, 53% (ClinVar), 71% (LOVD), and 71% (gnomAD), were editable, pathogenic transition mutations, of which 35-47% had \"ideal\" PAM sites. Of these mutations, 16-20% occur within a range of multiple PAM sites, enabling a variety of editing strategies. Further, in relevant patient data looking at three cohorts from Germany, Denmark, and China, we find that 44-76% of patients, depending on the presence of complex alleles, have at least one transition mutation with a nearby SaCas, SpCas, or Sa-KKH PAM site, which would allow for potential DNA base editing as a treatment strategy. Given the complexity of the genetic landscape of Stargardt, these findings provide a clearer understanding of the potential for DNA base editing approaches to be applied as ABCA4 gene therapy strategies.