Xlinked

Xlinked is a term used in genetics to describe traits and conditions associated with genes located on the X chromosome. In formal usage, the standard form is X-linked, but Xlinked appears in some databases, casual references, or branding contexts. The concept is central to sex-linked inheritance and applies to various phenotypes across humans and other species.

X-linked inheritance arises because males have one X and one Y chromosome, while females have two X chromosomes. In X-linked recessive patterns, affected males pass the mutated allele to all daughters, who become at least carriers if the mother contributes a normal X, but do not pass it to their sons. Affected females are rarer and typically occur with two mutated copies or in cases of skewed X-inactivation. In X-linked dominant patterns, affected males transmit the mutation to all daughters and none to their sons, whereas affected females have a 50% chance of transmitting to each child, with expression that can be variable.

Commonly cited examples of X-linked recessive conditions include color vision deficiencies such as red-green color blindness, hemophilia A and B, and Duchenne muscular dystrophy. Genetic testing often involves pedigree analysis and molecular testing of X-linked genes to confirm diagnosis and guide counseling.

Clinically, understanding Xlinked inheritance informs risk assessment for relatives, carrier testing, and reproductive decision-making. The term reflects a foundational concept in genetics regarding the chromosomal localization of disease-associated genes and how this location influences inheritance patterns.