COL4A3 and autosomal recessive polycystic kidney disease: The 3 disorders with the highest lifetime risk (>1.5 per 100,000), accounted for 24% of the overall lifetime risk and were caused by PKHD1 (autosomal recessive polycystic kidney disease), SLC12A3 (Gitelman syndrome), and COL4A3 (Alport syndrome) variants.