Sex-+Linked+Inheritance

You might be wondering HOW your son inherited the disease Hemophilia. The answer is Sex- Linked Inheritance. In order to understand this, you must first understand the basics of chromosomes. Each woman has two X chromosomes while a man has an X and a Y chromosome. The disease is only carried on the X chromosome which makes the disease more likely to be passed on from a mother to a son. This is because in order for the gender of the child to be male, the woman needs to give one of her X chromosomes and the man needs to give his Y chromosome. If the woman is a carrier of the disease, this means that she is carrying the allele for the disorder on one of her chromosomes, and the other one is healthy. The healthy chromosome is dominant which means that it "over rules" the unhealthy chromosome, but the mother is still carrying the disease and therefore is able to pass it on to her offspring. In your case, Susan was a carrier of the disease and passed on her unhealthy chromosome to Jeffery. Now another question might be in your mind. How did Susan become a carrier of the disease? Well Susan, it seems that your Grandfather had Hemophilia and passed on his unhealthy X chromosome to you making you a carrier. You had a 50% of chance of either passing on your healthy chromosome or your mutated chromosome. Unfortunately, you passed on your unhealthy chromosome resulting in your son having this disease, but that's why we're here to help!