Recessive mutations in the human <i>IQCB1/NPHP5</i> gene are associated with Senior-Løken syndrome (SLS), a ciliopathy presenting with nephronophthisis and Leber congenital amaurosis (LCA).
A deletion analysis of the NPHP1 gene was performed in each case, and NPHP5 mutation screening was performed in the absence of such deletion in patients with Senior Loken syndrome.
Null mutations in the human IQCB1/NPHP5 (nephrocystin-5) gene that encodes NPHP5 are the most frequent cause of Senior-Løken syndrome, a ciliopathy that is characterized by Leber congenital amaurosis and nephronophthisis.
In three isolated LCA patients, the authors identified large homozygous regions on chromosome 3 encompassing the IQCB1 gene, which has been associated with Senior-Loken syndrome (SLSN), characterized by nephronophthisis and retinal degeneration.
This region contained two known ciliopathy genes: NPHP3 (adolescent nephronophthisis) and IQCB1 (NPHP5), which is associated with Senior-Löken syndrome.
Third, 37 patients presenting with NPHP and retinitis pigmentosa (Senior-Løken syndrome [SLS]) were screened for NPHP5/IQCB1 mutations by direct sequencing.