Alumno

Sex-Linked Disorders

Color-blindness:
Occurs when there is a problem with the color-sensing granules (pigments) in certain nerve cells of the eye. These cells arecalled cones. They are found in the retina, the light-sensitive layer of tissue that lines the back of the eye.
Most color blindness is due to a genetic problem. (See:X-linked recessive) About 1 in 10 men have some form of color blindness. Very few women are color blind.

Hemophilia:
Lack of clotting factor in blood.
Mutations in the F8and F9 genes cause hemophilia.

Duchenne muscular dystrophy:
Is a recessive X-linked form of muscular dystrophy, which results in muscle degeneration, difficultywalking, breathing, and death.
Females are rarely affected and are more often carriers.

Down syndrome:
Also called Trisomy 21) is a genetic disorder that occurs inapproximately 1 of 800 live births. It is the leading cause of cognitive impairment
Genes on an extra copy of chromosome 21 are responsible for all characteristics associated withDown syndrome

Turner´s syndrome:
Turner syndrome is a genetic condition that only affects females. The condition was named after Dr Henry Turner who discovered it in1938. It is caused by an abnormal sex chromosome and affects about 1 in every 2,000 baby girls.
As height and sexual development are the two main characteristics of Turnersyndrome,

Klinefelter syndrome
Chromosomal condition that affects male sexual development. Males with this condition typically have small testes that do not produceenough testosterone,

XYY syndrome:
This produces a 47,XYY karyotype, which occurs in 1 in 1000 male births.
No, aggression is not seen more frequently in 47,XYY males.