A long-read genome sequencing approach to identify novel genes associated with accelerated aging phenotypes

哈勒曼-斯特雷夫综合征(HSS；OMIM 234100)是一种罕见的先天性综合征，以颅面畸形、身材矮小、眼睛畸形以及皮肤和头发的异常为特征，并具有独特的面部外观。到目前为止，其遗传基础和潜在的分子机制尚未揭开面纱。HSS属于加速衰老或孕期综合征的一组，它概括了生理性衰老和很早就与衰老相关的病理的特征。因此，识别孕激素综合征的致病基因也为研究和阐明衰老的生物学过程以及对心血管疾病、癌症或神经变性等与衰老相关的疾病的发展提供了一个非常强大的工具。在生理性衰老和与衰老相关的疾病中，细胞和分子机制的缺陷也被归因于各种程序性综合征，它们的遗传学基础被确定为影响染色质结构、基因组稳定性、转录控制、DNA损伤修复、核组织或表观遗传调节的突变。我们收集了30名HSS患者的独特队列，在初步研究中，我们已经应用了各种下一代测序(NGS)方法。我们确定了四个有希望的候选基因，初步功能分析的结果表明，它们的编码蛋白在涉及染色质相关过程和转录控制的共同机制中发挥作用。尽管如此，我们使用短读全外显子组测序(WES)和全基因组测序(WGS)策略进行的广泛的基因鉴定研究只在我们的HSS患者中发现了一小部分致病突变。因此，在下一个合乎逻辑的步骤中，我们的目标是使用PacBio技术在我们的HSS患者队列中应用长读WGS，以揭示特定的突变特征(例如，更大的缺失、重复或倒置)，这是短读测序方法无法检测到的。对于从生成的PacBio NGS数据集解释已识别的结构异常以及单核苷酸变体，我们将得到位于哥廷根的人类遗传学研究所MutationMining(MM)团队的专业知识和经验的支持。识别新的突变和基因将使我们能够更深入地了解HSS和加速衰老的发病机制和细胞过程。这些知识还将提高我们对生理衰老和与衰老相关的病理的理解。

Hallermann-Streiff syndrome (HSS; OMIM 234100) is a well-known, rare congenital syndrome, characterized by craniofacial dysmorphism, short stature, eye malformations as well as anomalies of skin and hair, and a distinctive facial appearance. Its genetic basis and underlying molecular mechanism have so far not been unveiled. HSS belongs to the group of accelerated-aging or progeroid syndromes, which recapitulate hallmark features of physiological aging and aging-associated pathologies at a very early age. Identification of disease-causing genes in progeroid syndromes thus also provides a very powerful tool to investigate and elucidate the biological processes of aging and to gain new insights into the development of aging-related diseases like cardiovascular disease, cancer or neurodegeneration. A variety of progeroid syndromes have been attributed to defects in cellular and molecular mechanisms that are also relevant in physiological aging and in aging-associated disease and their genetic basis has been identified as mutations affecting e.g. chromatin structure, genome stability, transcriptional control, DNA damage repair, nuclear organization or epigenetic regulation.We have collected a unique cohort of > 30 patients with HSS, and in preliminary studies, we have already applied various next-generations sequencing (NGS) approaches. We identified four promising candidate genes and the results of our initial functional analyses suggest that their encoded proteins act in a common mechanism involved in chromatin-related processes and transcriptional control. Still, our extensive gene identification studies using short-read whole-exome sequencing (WES) and whole-genome sequencing (WGS) strategies revealed causative mutations only in a small proportion of our HSS patients. In a next, logical step, we therefore aim at applying long-read WGS using the PacBio technology on our cohort of HSS patients to uncover specific mutation profiles (such as e.g. larger deletions, duplications, or inversions), which could not be detected in a short-read sequencing approach. For interpretation of identified structural aberrations as well as single nucleotide variants from the generated PacBio NGS data sets, we will be supported by the expertise and experience of the MutationMining (MM) team at the Institute of Human Genetics in Göttingen. Identification of novel mutations and genes will allow us to gain deeper insights into the genetic mechanisms and cellular processes that are involved in the pathogenesis of HSS and accelerated aging. Such knowledge will also improve our understanding of physiological aging and aging-associated pathologies.