Patient: Steven Mann
1. Steven Mann – Infant
2. Female sister
3. Maternal aunt – carrier status unknown
4. Mother – carrier
5. Maternal uncle – nonhemophiliac
6. Father
7. 2nd cousin – female – carrier status unknown
8. 2nd cousin – male – nonhemophiliac
9. Grandmother – carrier
10. Great Uncle – non-hemophiliac
11. Great Aunt – carrier status unknown
12. Grandfather
13. Great Uncle
14. Great great uncle – hemophiliac
15. Great great grandmother – carrier
16. Great great uncle
17. Great great uncle
Instructor's Note:
Explanation of Pedigree Chart: This pedigree chart shows a rare case of hemophilia skipping 2 generations. The last known case of hemophilia was in the infants(1) great great uncle (14). The hemophilia gene was passed to the infant from his mother(4) who inherited the trait from her mother(9) who inherited the trait from her mother(15). Children of a mother carrying the hemophilia gene have a 50/50 chance of inheriting the gene. Females that inherit the gene will be carriers and may pass the gene to their children. Males that inherit the gene will have hemophilia. Males 16, 10, 5, and 8 did not inherit the gene. It is not known if females with ?'s are carriers or not. The trait may be identified in these females through DNA testing of their blood. This is especially important to identify in females that may still have children. If the females are carriers, they have the weighty issue of deciding to have children who may be male hemophiliacs or female carriers or to not have children to stop the passing of the hemophilia gene.