Genetics and Pathobiology of Disorders of Keratinization

 描述（申请人提供）：角化障碍（DOK）是一种严重、罕见的遗传性皮肤病，其中皮肤的中央屏障功能被破坏，局部区域或整个皮肤表面的过度增殖代偿途径被激活。这导致表皮严重受损，不能充分保护免受细菌、化学和机械攻击或防止经表皮水分流失。在生命早期，这些疾病的后果可能是危及生命的，由于水疱和裂缝导致的感染易感性增加，由于蒸发热损失和表皮更新率增加导致的代谢需求急剧增加，以及各种相关的合并症和全身异常，这些疾病可能在整个生命中持续存在。先前的研究已经确定了这些疾病的70多个不同的基因，但临床经验和我们的数据显示，这些基因只能解释DOK的一部分遗传性，这表明了明显的基因座和表型异质性，超过20%的受试者在已知基因中没有突变。下一代测序为确定DOK基因提供了一个新的机会，我们已经成功地应用它来确定这些疾病的几个新的遗传原因。我们现在建议扩大我们的大型队列表型良好的DOK激酶，筛选常见致病基因的突变，并采用外显子组测序在那些没有常见DOK基因突变的受试者，以发现这些疾病的新的遗传原因。我们将采用患者来源的细胞和组织来询问已鉴定的新基因的功能，并将采用转基因皮肤等同物来研究和证明已鉴定突变的发病机制。对于以前未涉及DOK的有限数量的新基因，我们将使用CRISPR技术生成小鼠模型，以进一步研究已鉴定的突变对皮肤发育和生理学的影响。这些研究将继续确定表皮分化和自我更新的复杂过程的分子途径，并将为未来更详细的生物学研究提供关键背景。

 DESCRIPTION (provided by applicant): Disorders of keratinization (DOK) are severe, rare genetic skin disorders in which the central barrier function of the skin is disrupted and a compensatory pathway of hyper-proliferation is activated in either a localized area or throughout the entire skin surface. This results in a grossly compromised epidermis that fails to adequately protect against bacterial, chemical, and mechanical assault or to prevent transepidermal water loss. In early life, the consequences of these disorders can be life-threatening, with increased susceptibility to infection due to blistering and fissures, dramatically increased metabolic demands due to evaporative heat loss and increased epidermal turnover rate, and various associated comorbid conditions and systemic abnormalities which can persist throughout life. Prior studies have identified over 70 diverse genes for these disorders, yet clinical experience and our data show that these genes explain only a portion of heritability for DOK, which demonstrate marked locus and phenotypic heterogeneity, with greater than 20% of subjects without mutation in known genes. Next generation sequencing has provided a new opportunity to identify genes for DOK, and we have applied it successfully to identify several novel genetic causes of these disorders. We now propose to expand our large cohort of well-phenotyped DOK kindreds, to screen for mutations in common causative genes, and to employ exome sequencing in those subjects without mutation in common DOK genes to discover novel genetic causes of these disorders. We will employ patient-derived cells and tissue to interrogate the function of identified novel genes, and will employ transgenic skin equivalents to study and prove pathogenesis of identified mutations. For a limited number of novel genes not previously implicated in DOK, we will generate mouse models using CRISPR technology to further examine the effect of identified mutations on skin development and physiology. These studies will continue to identify molecular pathways central to the complex processes of epidermal differentiation and self-renewal, and will provide critical context for more detailed future biologc studies.