CFTR and cystic fibrosis: Various tools are available to help identify the clinical impact of a CFTR variant: (1) international mutations databases such as the Cystic Fibrosis Mutation Database (http://www.genet.sickkids.on.ca/), CFTR2 database (https://cftr2.org/) or UMD-CFTR database (http://www.umd.be/CFTR/); (2) CF registries, which may assist genetic counseling by providing aggregated clinical data associated with a given genotype; (3) bioinformatics prediction tools such as Polyphen or SIFT applications.