A stem cell-based platform for functional analysis of genetic variants in lung disease.

Advances in genetic and transcriptomic technologies have identified large numbers of genes and variants of potential importance to human disease. Determining the function of these genes and variants is a critical bottleneck in understanding disease etiology. Variants of uncertain significance (VUS) are highly prevalent in our genomes, but our ability to identify them significantly outpaces our ability to determine their molecular and clinical consequences. We developed a genetically tractable induced pluripotent stem cell (iPSC) based platform to investigate gene variant pathogenicity in lung disease, using primary ciliary dyskinesia (PCD) as a model. We identified an individual with a clinical diagnosis of PCD and a VUS in the gene Multiciliate differentiation and DNA synthesis associated cell cycle protein (MCIDAS). Through gene-editing of iPSC-derived airway basal stem cells (iBCs), we precisely defined the molecular and cellular pathogenicity of the variant providing a successful application of the iPSC system to diagnose a lung disease.