X-linked recessive

X-linked recessive refers to genetic conditions caused by changes in genes on the X chromosome. Since males have one X and one Y chromosome, a single affected X gene can cause the disorder. Females have two X chromosomes, so they usually need both to be affected for the disorder to appear. If only one X chromosome has the change, females are typically carriers without symptoms. Examples include hemophilia and Duchenne muscular dystrophy. These conditions are inherited when the affected gene comes from the mother, and males are more often affected because they don’t have a second X to compensate.