How do people inherit color vision deficiency?
The types of color vision deficiency have different patterns of inheritance. Red-green color vision defects and blue cone monochromacy are inherited in an X-linked recessive pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. Blue-yellow color vision defects are inherited in an autosomal dominant pattern, which means one copy of the altered OPN1SW gene in each cell is sufficient to cause the condition. Complete achromatopsia is inherited in an autosomal reces
