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Jason A Chen

Publications and source records attributed to Jason A Chen.

2 recordsLinked to original sources
bioRxiv2016

Rare copy number variants in NRXN1 and CNTN6 increase risk for Tourette syndrome

Tourette syndrome (TS) is highly heritable, although identification of its underlying genetic cause(s) has remained elusive. We examined a European ancestry sample composed of 2,435 TS cases and 4,100 controls for copy-number variants (CNVs) using SNP microarrays and identified two genome-wide significant loci that confer a substantial increase in risk for TS (NRXN1, OR=20.3, 95%CI [2.6-156.2], p=6.0 x 10-6; CNTN6, OR=10.1, 95% CI [2.3-45.4], p=3.7 x 10-5). Approximately 1% of TS cases carried one of these CNVs, indicating that rare structural variation contributes significantly to the genetic architecture of TS.

Genetics↗
bioRxiv2016

CRISPR-Cas9 targeted deletion of the C9orf72 repeat expansion mutation corrects cellular phenotypes in patient-derived iPS cells

The large hexanucleotide (GGGGCC) repeat expansion in the non-coding promoter region of C9orf72 is the leading cause of Frontotemporal Dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS). Mechanisms underlying neurodegeneration are not clear, and both a C9orf72 loss of function and a gain of toxicity, in the form of RNA foci or dipeptide repeat deposition, are implicated. CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9-mediated genome editing is an attractive strategy for disease modeling and therapeutic intervention. Here we show that this system can be utilized to completely remove the large repeat expansion mutation within C9orf72 in patient-derived induced pluripotent stem (iPS) cells. Removal of the mutation prevented RNA foci formation and promoter hypermethylation, two phenotypes of the C9orf72 mutation. Interestingly, these changes did not significantly alter C9orf72 expression at the mRNA or protein level. This work provides a proof-of-principle for the use of CRISPR-Cas9-mediated excision of the pathogenic C9orf72 repeat expansion as a therapeutic strategy in FTD/ALS.\n\nOne Sentence SummaryCRISPR-Cas9-mediated excision of the large C9orf72 repeat expansion mutation rescues RNA foci formation and promoter hypermethylation without altering C9orf72 transcript and protein expression.

Neuroscience↗