An estimated 10,000 rare Mendelian genetic disorders affect, in aggregate, one in twelve individuals. Importantly, just over half of these diseases have a known genetic cause. This leaves thousands of disease genes waiting to be discovered and millions of affected individuals without a diagnosis. The investigators will address these critical issues in genomic medicine by using genome sequencing and other 'omics technologies to assess patients whose comprehensive clinical workups have failed to yield a diagnosis. The hypothesis is that, when carefully selected, these undiagnosed disease patients will be a rich resource for new disease gene discovery.
This study is the research arm of the UW Undiagnosed Disease program (UW-UDP). The primary objective of this study is to discover new disease genes and expand the known phenotypes of rare Mendelian disorders. The secondary objectives are: a) Diagnose individuals with genetic disorders who have not been diagnosed using conventional clinical means and provide them with actionable knowledge to manage their disorders; b) Improve our understanding of the pathobiology of genetic disorders and the relationships between genomic variation and disease; and c) Develop and trial novel diagnostic technologies and analytics.
These objectives will be achieved through three aims:
Aim 1: Identify candidate disease variants in individuals suspected of an undiagnosed genetic disorder through the use of trio short read genome sequencing and data sharing with the rare disease databases GeneMatcher and MatchMaker Exchange.
Aim2: Further evaluate those individuals not diagnosed in Aim 1 by using novel 'omics technologies and bioinformatics algorithms. These approaches include a) ultra-long read de novo assembly-based genomic sequencing; b) RNA-Seq; c) epigenomics profiling, and d) conformational analysis of chromatin organization.
Aim 3: Provide functional assessments of selected candidate disease genes and genomic variants discovered in Aims 1 and 2 through collaborations with UW and external model organism researchers. These efforts will be facilitated through the use of a UW model organism researcher database that is linked to the Canadian Rare Diseases Models and Mechanisms Network database and an emerging global network of model organism researcher databases.
This research project is closely integrated with the UW-UDP's comprehensive clinical evaluations of undiagnosed patients. The standard clinical care component entails patient referral, collection and pre-visit assessment of medical records, and clinic visits for extensive phenotyping at the beginning of the study and for the return of results at the end of the study. The research workflow includes genome sequencing, data sharing with global disease gene discovery networks, and follow-up studies to determine causality of variants identified by genetic testing. This study will advance understanding of the pathobiology of genetic disease, improve clinical diagnostics, and aid in the diagnosis and management of individuals with previously undiagnosed rare disorders both within Wisconsin and beyond its borders.
