JAG1 of all trades, master of CKD? The role of JAG1 in autosomal dominant tubulointerstitial kidney disease.

The current study by Menguy et al. describes JAG1 as a novel candidate gene for the spectrum of autosomal dominant tubulointerstitial kidney disease. Patients have been shown to develop fibrosis and chronic kidney disease, when distinct pathogenic germline variants occur in JAG1. Interestingly, genetic alterations in the Jagged1/Notch2 pathway can cause the variable appearance of Alagille syndrome, which may also occur in the very same families. Haploinsufficiency is the likely pathomechanism, but future work will need to define the underlying mechanisms.