 A small number of pathogenic variants were found in more than one family.The 48% are truncating mutations (nonsense, frameshift or complex), 37% non-truncating (missense or in-frame insertions/deletions), 10% splice site mutations, and 5% other type (large deletions, Alu insertions or 5’UTR mutations).Functional investigations in "Xenopus Levis" oocytes and mammalian cells enabled these "CLCN5" mutations to be classified according to their functional consequences.