CLDN2 and nephrolithiasis: The index variant is in the gene body of MORC4 and CLDN2. Although, several high CADD score variants within different gene bodies are in the CS, we consider the gene CLDN2 as a highly plausible candidate due to its known role in nephrolithiasis development according to OMIM-ID 300520 and the kidney phenotypes of CLDN2 knock-out mouse models33.