PKD1 and autosomal dominant polycystic kidney disease: Biallelic PKD1 or PKD2 pathogenic variants have been reported in ADPKD patients with very early-onset of symptoms.30 We have found biallelic PKD1 reported variant p.Arg3277Cys in a 43-year-old Azeri female whose age of onset was 26 (Table 1 and Table S2).