No father to son transmission occurs but all daughters of affected fathers will be carriers. Depending on the condition, examination of a carrier female may reveal some mild manifestation. The first affected son in a family may inherit the changed gene from a carrier mother or may be the result of a new genetic change. X-Linked Recessive Pedigree Click here for a key to the symbols. There are very few X-linked dominant traits.
Affected females transmit the trait to half of their sons and half of their daughters.
There are usually twice as many affected females as affected males but affected females often express the condition to a milder degree. X-Linked Dominant Pedigree Click here for a key to the symbols. Occasionally, some conditions inherited in this manner are apparently lethal in males and this manifests as male fetuses being miscarried. Often a woman will report having several miscarriages and will have fewer sons than daughters. X-Linked Dominant Pedigree Demonstrating Male Lethality Click here for a key to the symbols.