A homozygous mutation in INVS causing juvenile nephronophthisis with abnormal reactivity of the Wnt/beta-catenin pathway

Mutations in the INVS gene coding for inversin have been identified in patients with nephronophthisis type 2 (NPHP2), typically causing infantile onset of ESRD and potentially associated with situs inversus. We report a novel family with a homozygous INVS mutation (c.2695 C > T; p.Arg899X) deleting the C-terminus of inversin. Both affected patients had juvenile ESRD and were discordant for situs inversus. The end-stage kidneys showed chronic interstitial nephritis with cysts and abnormal expression of β-catenin and Dishevelled-1 supporting up-regulated canonical Wnt pathway in tubular cells. This case shows that INVS mutation can cause juvenile nephronophthisis with abnormal reactivity of the Wnt/β-catenin pathway.