X-linked

Relating to the genes situated on the X chromosome.


Term describing a gene that is located on the X chromosome, one of the two sex chromosomes; also a trait or genetic disorder associated with such a gene. Such traits are recessive, meaning that the trait will be masked in the presence of a dominant gene. That means that X-linked traits rarely affect women, because both of their X chromosomes must carry the defect; women who have just one abnormal gene are unaffected but are called carriers, because they can pass the trait on to their children. However, men have only one X chromosome (paired with a Y), so any X-linked defect will show itself. Among the most common X-linked genetic disorders are hemophilia, agammaglobulinemia, color blindness, fragile x syndrome, muscular dystrophy (Duchenne type), and spinal ataxia. During genetic counseling, counselors will gather information from prospective parents or parents-to-be about their medical and genetic history and put that information into the form of a pedigree.


Denoting characteristics that are transmitted by genes on the X chromosome.


Situated on the X chromosome, certain genes linked to the sex chromosome exhibit a distinctive inheritance pattern that persists across successive generations. This pattern is referred to as X-linked inheritance, as it primarily affects individuals based on their sex chromosome composition. In this mode of inheritance, specific traits or disorders associated with these genes are more commonly observed in males, who possess a single X chromosome, while females, with two X chromosomes, may display a carrier state or exhibit varying degrees of expressivity. Understanding the mechanisms of X-linked inheritance is pivotal in comprehending the transmission and manifestation of genetic conditions in a family.


 


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