Pedigree

Question

1. What would a pedigree of Greg and Olga’s families look like? Concentrate simply on family relationships and affected persons.   The pedigree of Greg family would have one person with factor Vlll deficiency, four with myotonie dystrophy, two people died and six remained unaffected.  The pedigree of Olga's family would have one with factor Vlll, and one with hemophilia A, one with hemophilia, several that remained unaffected.

Questions

1. Do autosomal dominant disorders skip generations? Yes they can.
2. Could Greg or his mother be carriers of the gene that causes myotonic dystrophy? yes they could be carriers and not be affected.
3. Is there a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy (MD) gene? yes there is that possibility.
4. Symptoms of myotonic dystrophy sometimes don’t show up until after age fifty. What is the possibility that Greg’s cousin has inherited the MD gene? Its a fifty fifty chance you never know.
5. What is the possibility that Greg and Olga’s children could inherit the MD gene? fifty fifty.       

Questions

1. What are the hallmarks of an autosomal recessive trait?It is a trait that is mainly likned with the sex gene.
2. What does consanguineous mean? Why is this concept especially important when discussing recessive genetic disorders?
3. What is it about the inheritance pattern of factor VIII deficiency seen in Greg and Olga’s pedigree that point toward it not being an autosomal recessive trait?

Questions

1. What are the characteristics of X-linked recessive inheritance?
2. Why does a son never inherit his father’s defective X chromosome? 
3. What is required for a woman to display a sex-linked recessive trait?
4. Return to the pedigree drawn earlier for Greg and Olga; mark those persons who are carriers of the factor VIII deficiency gene.
5. What is the chance that Olga carries the gene for factor VIII deficiency? Calculate the probability that she will pass it to her offspring. Will male children be affected in a different way than female children?
6. What is the chance that Greg carries the factor VIII gene? Can he pass the gene on to his sons? His daughters? How will each be affected?

Questions

1. What is the second equation?
2. The incidence of cystic fibrosis in Hispanic Americans is 1/4500 while in African Americans cystic fibrosis is seen in 1 of every 15,000 births. What is the carrier frequency for each of these populations?
3. What is the probability of two Hispanic Americans having a child with cystic fibrosis, given that there is no history of the disease in either’s family?
4. Carol is an African American woman who does not suffer from CF. Both of her parents are healthy but her brother has cystic fibrosis. Carol is planning a family with her husband Marcus, who is also African American but who has no history of CF in his family. What is the probability of their having a child with CF

   
   

   Questions

   1. What are some of the risks and benefits of genetic testing as it relates to legal (not medical) issues?
   2. Do you think an unintended consequence of genetic testing could be that people would be less liable to seek medical care out of fear that they could later be denied life or health insurance? What laws should be used to govern the use of genetic data of this type?