Systematic Discovery and Correction of Splicing Defects caused by Retroelement Insertions
The
objectives of this proposal are to systematically uncover transposable element
(TE) insertions as an under-explored genetic cause of childhood Mendelian
diseases (Aim 1) and to characterize how the insertions influence RNA splicing
and screen antisense-oligonucleotides (ASO) to correct splicing defects (Aim
2). This project will therefore be supportive of our long-term goal of defining
the role of TE insertions in diverse human diseases beyond Mendelian diseases
and provide the basis for effective diagnosis and treatment.
My laboratory focuses
on aberrations in repetitive DNA, particularly transposable elements,
and how they affect RNA in various human diseases, including cancer, Mendelian
disorders, and complex neurological disorders. My expertise is in large-scale
genomic and transcriptomic analysis of human TEs and splicing. In this
proposal, we will analyze genome sequences from multiple rare childhood disease
cohorts using Tea (Transposable Element Analyzer), a computational method I
have developed to identify TE insertions at single-nucleotide resolution
(Science 2012; Neuron 2015).
As numerous studies,
including our own, indicate that TE insertions greatly influence gene
transcripts, we will perform RNA-seq analysis on selected candidates to
understand these insertional effects. For TE insertions that are confirmed as
splice-altering, we will design and screen ASOs to restore normal splicing. Our
preliminary data demonstrates the feasibility of splicing modulation therapy
and has yielded high quality insertion candidates to justify this line of
investigation.
Given that genetic causes
of a significant fraction of cases with Mendelian disorders remain unresolved
with conventional single-nucleotide variant analysis, we expect our focused and
systematic investigation to provide insights into the relevance and importance
of TE insertions as a previously underappreciated mechanism at work in
Mendelian disorders as well as providing a foundation for effective diagnosis
and novel therapeutics to greatly improve childhood health.