For the following question, you are encouraged to refer to the American Pregnancy Association article, “In Vitro Fertilization: IVF,” and the Multimedia presentation, “The Marvel of Prenatal Development,” listed in the Resources.
- What are the similarities and differences between natural conception and in-vitro fertilization (IVF)?
For the following questions, you are encouraged to refer to the following materials listed in the Resources: the “Human Genetics” chapter in the Ahluwalia e-book; the “Genes in Pedigree” chapter in the Strachan and Read Internet resource; the “Human Pedigree Analysis” chapter in the Griffiths, Gelbart, Miller, and Lewontin Internet resource; and the “Genetic Counseling” Internet article from the Nemours Foundation.
- How are chromosomes passed down from parents to children? Why is the haploid number of chromosomes from the egg and the sperm important in order for a child to have the correct number of chromosomes? What could happen if a child has less or more than 46 chromosomes?
- How are Punnett squares useful in determining how genes are passed down from each parent to a child?
- What is a family pedigree? How are family pedigrees used to determine the chances of familial genes being passed down to offspring? How could a genetic counselor use a family pedigree to advise parents about the chances of a child inheriting familial genes?
Scenario One – Our patient seeks genetic counselingKayla has a family history of Duchenne muscular dystrophy (DMD), which is a sex-linked trait. The patient wishes to know her risk of having an affected child. Her grandmother was a known carrier. DMD is an inherited disorder that involves progressive muscle weakness. It affects approximately 1 in 3500 male births worldwide and is inherited in an X-linked recessive pattern.
Click here to learn more about DMDThe following pedigree was drawn up by the genetic counselor. Our patient, Kayla, is #13.
What are the relationships between:
Testing would establish her status as either a carrier or a noncarrier.