biostudies-literatureDel Cano-Ochoa FNIDDK NIH HHSNINDS NIH HHSMICIU1598-1605https://www.ebi.ac.uk/biostudies/studies/S-EPMC7521996biostudies-literatureUnknown22(10)<h4>Purpose</h4>Pathogenic autosomal recessive variants in CAD, encoding the multienzymatic protein initiating pyrimidine de novo biosynthesis, cause a severe inborn metabolic disorder treatable with a dietary supplement of uridine. This condition is difficult to diagnose given the large size of CAD with over 1000 missense variants and the nonspecific clinical presentation. We aimed to develop a reliable and discerning assay to assess the pathogenicity of CAD variants and to select affected individuals that might benefit from uridine therapy.<h4>Methods</h4>Using CRISPR/Cas9, we generated a human CAD-knockout cell line that requires uridine supplements for survival. Transient transfection of the knockout cells with recombinant CAD restores growth in absence of uridine. This system determinGenetics in medicine : official journal of the American College of Medical GeneticsCell-based analysis of CAD variants identifies individuals likely to benefit from uridine therapy.PMC7521996R01DK99551BFU2016-80570-RU54 NS115198R01 DK099551R01 NS109149Houlden HElpeleg OKarimiani EGAlmannai MRosenfeld JAMuriello MLiu PToosi MBMaroofian RCostain GDel Cano-Ochoa FWolfe LARamon-Maiques SAbedalthagafi MNg BGSutton VRCohn RDAl-Otaibi AShimon EPatel HFreeze HHManzini MCfalseCell-based analysis of CAD variants identifies individuals likely to benefit from uridine therapy.<h4>Purpose</h4>Pathogenic autosomal recessive variants in CAD, encoding the multienzymatic protein initiating pyrimidine de novo biosynthesis, cause a severe inborn metabolic disorder treatable with a dietary supplement of uridine. This condition is difficult to diagnose given the large size of CAD with over 1000 missense variants and the nonspecific clinical presentation. We aimed to develop a reliable and discerning assay to assess the pathogenicity of CAD variants and to select affected individuals that might benefit from uridine therapy.<h4>Methods</h4>Using CRISPR/Cas9, we generated a human CAD-knockout cell line that requires uridine supplements for survival. Transient transfection of the knockout cells with recombinant CAD restores growth in absence of uridine. This system determin2020-01-01T00:00:00Z2020 Oct2026-05-01T01:01:28.91Z2020-10-29T09:32:50ZS-EPMC75219963246166710.1038/s41436-020-0833-2