Hemophilia The Royal Disease

August 22, 2020 Hemophilia “The Royal Disease” Question #1 a. What is the probability that her other son was hemophilic? There is a 50% chance that he was hemophilic since the mother was a carrier of the disease. Women have two X chromosomes, and to be a carrier one X chromosome is normal while the other X chromosome is abnormal. b. What is the probability that her daughter was a carrier? Hemophilic? There would still be a 50% chance because it would be coming from the mother (carrier) who has a normal X chromosome, and abnormal X chromosome. The daughter could not be a hemophilic because that would result in both her X chromosomes being abnormal which would result in immediate death. c. What is the probability that both children were normal? Again, there would be a 50% chance of normalcy because hemophilia is carried on X chromosome. The mother is were you get the X chromosome from and since she has two (a normal and abnormal chromosome) there is 50/50 chance of being either. Question #2 a. Looking at the pedigree of the royal family, identify which of Beatrice’s children received the hemophilic gene; why can you make this conclusion? Three of her children received the hemophilic gene. Her daughter Eugenie was a carrier while two of her sons (Leopold and Maurice) were both hemophilic. This conclusion can be made because on the pedigree is shows Leopold and Maurice’s boxes completely field in which represent hemophiliacs. While Eugenie’s circle was only half field representing carriers of the gene. b. Notice that Beatrice’s daughter, Eugenie, married King Alfonso XIII of Spain and had six children, one of whom was the father of Juan Carlos, the current King of Spain. Would you predict that Juan Carlos was normal, a carrier, or a hemophilic? Juan Carlos would be normal since both his parents were normal. Question #3 a. What are the probabilities that all four of the girls were carriers of the allele hemophilia? There would be about a 50% chance of each girl being a carrier of the hemophilia gene, and a 1/16 chance for all four. b. Supposing Alexis had lived and married a normal woman, what are the chances that his daughter would be a hemophiliac? If he did live and end up marrying a normal woman then his daughter would have 0% chance of being a hemophiliac. For a female to be a hemophiliac both X chromosomes would have to be abnormal. c. What are the chances his daughters would be carriers? There would be a 100% chance that his daughters would be carriers because only females can carriers of hemophilia. d. What are the chances that his sons would be hemophiliacs? Since hemophilia is carried on the X chromosome, the sons would have 0% chance at being hemophiliacs. Because they receive a Y chromosome from the father, and an X chromosome from the mother. Question #4 a. According to Eugene’s argument, what was the likely hemophilic status of Eugene’s mother and grandmother? What about his father and grandfather? Is this argument plausible? The grandmother had to of been a carrier of hemophilia and passed the X chromosome to her daughter (his mother) for his argument to be true. It even could have some truth behind it because there is not a lot of information for the pedigree to be factual. So yes the argument could be plausible. b. How plausible is it that Eugene inherited both hemophilia and the last name from the royal family? It is very likely that he could have inherited hemophilia, but not the last name. Question #5 a. If you learned that one of the two sons was a hemophiliac, what are the possible explanations for this event? The mother would have had to be a carrier of hemophilia. b. “Queen Victoria might have been illegitimate” what are the chances of this scenario? More research would have to be done for this statement to be true because they would have to look at her mother to see if she was a carrier. Because again hemophilia is carried on the X chromosome not the Y chromosome.