The highest lifetime risk (> 1.5 per 100,000) was estimated for nephropathies caused by variants in PKHD1, SLC12A3, and COL4A3 associated with autosomal recessive polycystic kidney disease, Gitelman syndrome, and Alport syndrome, respectively. The gene discussed is COL4A3; the disease is autosomal recessive polycystic kidney disease.