Table 2 stratifies the 34 ATS patients with heterozygous COL4A3/COL4A4 mutations according to the site and type of mutations: of those with substitutions of the glycine amino acid in the collagenous domains, 19% developed ESRD, whereas heterozygotes for loss‐of‐function variants showed a more aggressive disease (66% with ESRD) and a lifetime probability of ESRD significantly higher than for carriers of glycine substitution (log rank 5.86, p = 0.015, Figure 1, Panel B). Here, COL4A4 is linked to Andersen-Tawil syndrome.