Among the 10%–15% of patients suspected to have ADPKD who have no explaining variants in either PKD1 or PKD2, next-generation sequencing (NGS) has identified several other genes in which variants cause ADPKD, including DNAJB11 (5), GANAB (6), ALG9 (7), and more recently, IFT140 (8) and ALG5 (9). The gene discussed is ALG9; the disease is autosomal dominant polycystic kidney disease.