Opsin 1, Short Wave Sensitive (OPN1SW)

OPN1SW belongs to the G-protein coupled receptor 1 family, opsin subfamily. It encodes the blue cone pigment gene which is one of three types of cone photoreceptors responsible for normal color vision. Defects in this gene are the cause of tritan color blindness (tritanopia). Affected individuals lack blue and yellow sensory mechanisms while retaining those for red and green. Defective blue vision is characteristic.

The blue cone ERG was unrecordable in patients with congenital tritanopia but within the normal range in those with DIJOA. Although far less common than the X-linked red-green forms of colorblindness, the prevalence of tritanopia may be as high as 1 in 500 in some populations.