The request
“A hemophilia A pedigree: an unaffected father and carrier mother have an affected son, a carrier daughter, an unaffected son and an unaffected daughter; the carrier daughter and an unaffected partner have an affected son, a carrier daughter and an unaffected son.”
Then tryMark the affected son in generation three as the proband.Add a deceased affected maternal grandfather.
What is in this drawing
Read the decisions behind it.
01X-linked carrier
The mother carries the altered X chromosome.
02Affected males
Two sons show the condition.
03Transmission
A carrier daughter can pass the variant to a son.
Use this pedigree to explain the typical X-linked recessive pattern in a family history.
More like this
Other examples in this family.
FAQ
Common questions
Why are males more often affected?
Males have one X chromosome, so one disease-associated change on it can cause an X-linked recessive condition.
What does carrier-x mean?
It marks a female who carries a disease-associated variant on one X chromosome.
Can an unaffected male pass hemophilia A to his son?
No. A father passes a Y chromosome, not his X chromosome, to a son.