NPHP1 — Nephrocystin 1

Illustration of the eye cross-section showing the retina at the back of the eye
Illustration of the eye cross-section showing the retina at the back of the eye

NPHP1 (BBS22) encodes nephrocystin-1, a protein that localizes to the transition zone of primary cilia and to cell-cell junctions. Originally identified as the cause of nephronophthisis, it was later associated with BBS and other ciliopathies.

Gene description: NPHP1 (BBS22) encodes nephrocystin-1, a protein that localizes to the transition zone of primary cilia and to cell-cell junctions. Originally identified as the cause of nephronophthisis, it was later associated with BBS and other ciliopathies.

Clinical significance: Mutations cause nephronophthisis type 1, Senior-Løken syndrome, Joubert syndrome, and BBS22. Large homozygous deletions are the most common mutation type.

Inheritance: Autosomal Recessive