DD1 patients have been described who carried pathogenic variants in both the CLCN5 and other genes, such as the NPHS2 gene (Zaniew et al. 2017) encoding for podocin (a key protein expressed by podocytes) or the CFTR, SCNN1A and SCNN1B genes (Zhang et al. 2017b), all of which are involved in cystic fibrosis (MIM #219700) or cystic fibrosis-like diseases. This evidence concerns the gene CLCN5 and cystic fibrosis.