In a study on 304 children with the clinical diagnosis of ARPKD and detected PKHD1 variants it was found that patients with either two missense variants affecting the amino acids 709–1837 or a null variant and a missense variant in this region less frequently showed progression to chronic kidney failure when being compared during their follow-up when compared to patients with variants affecting other regions of PKHD1. The gene discussed is PKHD1; the disease is chronic renal failure syndrome.