The product of this gene belongs to the small leucine-rich proteoglycan (SLRP) family of proteins. Defects in this gene are the cause of congenital stationary night blindness type 1 (CSNB1), also called X-linked congenital stationary night blindness (XLCSNB). CSNB1 is a rare inherited retinal disorder characterized by impaired scotopic vision, myopia, hyperopia, nystagmus and reduced visual acuity. The role of other SLRP proteins suggests that mutations in this gene disrupt developing retinal interconnections involving the ON-bipolar cells, leading to the visual losses seen in patients with complete CSNB.