Heredity of Two Types of Normal Colour Vision

Molecular Genetics of Human Visual Pigments

“…Female trichromats show a trimodal distribution in which two modes, each representing approximately one quarter of the population, coincide with the male modes, while the third mode, representing one half of the population, lies in the interval between them (63). The segregation of Rayleigh matches within a family indicates that this variability is an X-linked trait and that the central mode is comprised of heterozygous females (89).…”

Molecular genetics of human color vision

“…Females with normal color vision showed a third and larger group with intermediate values of match midpoints (Neitz and Jacobs, 1986). A similar independently described Rayleigh match variability fitted transmission by X-linked inheritance in families (Waaler, 1967). These observations pointed to the presence of two common spectrally different forms of the red pigment gene on the X chromosome.…”

“…Considerable variation in the severity of these defects has been observed. In addition, subtle variations in color perception among individuals with normal color vision have been reported (Waaler, 1967;Neitz and Jacobs, 1986;Winderickx et al, 1992 b;Elsner and Bums, 1987). The cloning and characterization of the genes that encode the rod and cone photopigment apoproteins ' Departments of Medicine and Genetics, University of Washington, Seattle, Washington.…”

Sex-related differences in peripheral human color vision: A color matching study

“…More recently, Kuehni (2001) investigated the appearance of the four unique or focal colors, red, green, blue, and yellow, and found that there is a difference in mean unique hue settings between males and females. Other studies have also reported sex-related differences with unique hues (Cobb, 1975;Kalmus & Case, 1972;Richards, 1967;Volbrecht, Nerger, & Harlow, 1997;Waaler, 1967). Females, particularly color normal carriers of color deficiency, have been shown to exhibit a wider Rayleigh matching range than males (Birch, Young, & David, 1991).…”