Down syndrome arises from the triplication of a subset of genes on chromosome 21 (HSA21). Individuals with DS uniformly demonstrate some degree early onset Alzheimers disease. Recent studies have suggested triplication of genes on HSA21, other than APP, contribute to the disruption of beta amyloid (Abeta) processing in mice. Whether similar pathological mechanisms are observed in human DS cells, as well as what subset of HSA21 genes are responsible for this disruption, remain unknown. We have developed a simple but novel approach using CRISPR gene editing techniques and DS cell culture models which will allow for knockdown of a single HSA21 copy, while leaving the other two copies intact. With this approach, we can systematically identify the subset of HSA21 genes most likely to contribute to the altered Abeta processing. Identification of the subset of HSA21 genes most responsible for AD in DS is not only critical for understanding pathological mechanisms, but also for devising appropriate therapies for treatment of this disorder.
Down Syndrome (DS) is caused by a triplication of genes on chromosome 21 (HSA21) and gives rise to early onset Alzheimers disease. Recent work suggests that genes other than APP on HSA21 contribute to AD pathogenesis. The current proposal incorporates several technological methods that allow for silencing of individual and clusters of genes in one HSA21 copy, leaving the other two intact. This approach will allow for systematic testing to identify which subset of genes the AD phenotype in DS.
