Genetics Color blindness

x-linked recessive inheritance

color blindness typically inherited. commonly inherited mutations on x chromosome mapping of human genome has shown there many causative mutations—mutations capable of causing color blindness originate @ least 19 different chromosomes , 56 different genes (as shown online @ online mendelian inheritance in man (omim)). 2 of common inherited forms of color blindness protanomaly (and, more rarely, protanopia – 2 known protans ) , deuteranomaly (or, more rarely, deuteranopia – 2 referred deutans ). both protans , deutans (of deutans far common) known red–green color-blind present in 8 percent of human males , 0.6 percent of females of northern european ancestry.

some of inherited diseases known cause color blindness are:

cone dystrophy
cone-rod dystrophy
achromatopsia (a.k.a. rod monochromatism, stationary cone dystrophy or cone dysfunction syndrome)
blue cone monochromatism (a.k.a. blue cone monochromacy or x-linked achromatopsia)
leber s congenital amaurosis
retinitis pigmentosa (initially affects rods can later progress cones , therefore color blindness).

inherited color blindness can congenital (from birth), or can commence in childhood or adulthood. depending on mutation, can stationary, is, remain same throughout person s lifetime, or progressive. progressive phenotypes involve deterioration of retina , other parts of eye, forms of color blindness can progress legal blindness, i.e., acuity of 6/60 (20/200) or worse, , leave person complete blindness.

color blindness pertains cone photoreceptors in retinas, cones capable of detecting color frequencies of light.

about 8 percent of males, , 0.6 percent of females, red-green color blind in way or another, whether 1 color, color combination, or mutation. reason males @ greater risk of inheriting x linked mutation males have 1 x chromosome (xy, y chromosome carrying altogether different genes x chromosome), , females have 2 (xx); if woman inherits normal x chromosome in addition 1 carries mutation, not display mutation. men not have second x chromosome override chromosome carries mutation. if 8% of variants of given gene defective, probability of single copy being defective 8%, probability 2 copies both defective 0.08 × 0.08 = 0.0064, or 0.64%.