X-Linked Disorders:

Red-green color blindness or vision deficiency is a common grouping of disorders, affecting up to 10% of men and 1% of women1. Pathogenic changes in the OPN1LW, OPN1MW, and OPN1SW genes on the X chromosome are known to cause partial and complete forms of red-green color vision deficiency (28). There are multiple types of red-green color vision deficiency, each with slightly different phenotypes:

• Deuteranomaly is a partial red-green color vision deficiency that causes certain shades of green to look more red. This is the most common red-green color deficiency (27).

• Protanomaly is a partial red-green color vision deficiency that causes certain shades of red to look green and less bright (27). 

• Protanopia and deuteranopia are both complete red-green color vision deficiency, meaning that people with these conditions are unable to tell the difference between red and green at all (27).

Written by Abigail Sayers; Images by Abigail Sayers unless otherwise noted

Reviewed and Edited by Rachel Baer, MSc, and Andy McCarty, MS, LGC, CGC

Learn More About Genetics:

• Sample Types

• Prenatal and Fetal Testing

• Aneuploidies

• Cytogenetics

Learn More About the X Chromosome:

• The X Chromosome

• X and Y Chromosomal Aneuploidies

• DMD and BMD

• Hemophilia A

• Alport Syndrome

• Fabry Disease

• Fragile X Syndrome

• Charcot-Marie-Tooth (CMT)