X-linked dominant inheritance

Main Article: <a href="/facts/Sex_linkage/buXJkWJg">Sex linkage</a>

X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of <a href="/facts/Genetics/bu8wne0A">genetic</a> <a href="/facts/Heredity/t0aMmRWx">inheritance</a> by which a <a href="/facts/Dominant_gene/DsvtPyQU">dominant gene</a> is carried on the <a href="/facts/X_chromosome/hpJxhSUr">X chromosome</a>. As an inheritance pattern, it is less common than the <a href="/facts/X-linked_recessive_inheritance/HDoKvzId">X-linked recessive</a> type. In medicine, X-linked dominant inheritance indicates that a gene responsible for a <a href="/facts/Genetic_disorder/hFqt2NLn">genetic disorder</a> is located on the X chromosome, and only one copy of the <a href="/facts/Allele/8FxCS9KA">allele</a> is sufficient to cause the disorder when inherited from a parent who has the disorder. In this case, someone who <a href="/facts/Gene_expression/alCPohLR">expresses</a> an X-linked dominant allele will exhibit the disorder and be considered affected. The pattern of inheritance is sometimes called criss-cross inheritance.
X-linked dominant traits do not necessarily affect males more than females (unlike <a href="/facts/X-linked_recessive/HDoKvzId">X-linked recessive</a> traits). The exact pattern of inheritance varies, depending on whether the father or the mother has the trait of interest. All fathers that are affected by an X-linked dominant disorder will have affected daughters but not affected sons. However, if the mother is also affected then sons will have a chance of being affected, depending on whether a dominant or recessive X chromosome is passed on. When the son is affected, the mother will always be affected. Some X-linked dominant conditions are embryonic lethal in males, making them appear to only occur in females.

X-linked dominant inheritance open-in-new

X-linked dominant inheritance