JAG1 and Alagille syndrome: Alagille syndrome (ALGS) is one such rare heritable disorder that is predominantly caused by loss‐of‐function variants in JAG1 (in 94.3% of ALGS patients [of which 87% are haplo‐insufficient], another 2.5% has NOTCH2 variants, 3.2% of patients remains unknown) and has an estimated incidence of 1:30,000 live births (Gilbert et al., 2019).