Myotonic Dystrohealthy Generation Case Summary
2. Do autosomal dominant disorders skip generations?
No, autosomal dominant disorders do not skip generations.
3. Could Greg or his mother be carriers of the gene that causes myotonic dystrophy?
No, according to the pedigree neither Grey nor his mother have the disease; therefore, neither one can be a carrier.
4. Is there a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy (md) gene?
No, there is not a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy. This is because Greg’s grandfather did not have the gene.
5. What is the possibility that Greg and Olga’s children could inherit the md gene?
There is no possibility that Greg and Olga’s children could inherit the md gene. This is because neither Greg nor Olga have the md …show more content…
gene.
Resources
Human Genetics for First Year Students: Pedigree Construction http://www.uic.edu/classes/bms/bms655/lesson3.html http://education-portal.com/academy/lesson/pedigree-analysis-in-human-genetics-inheritance-patterns.html ~11 min tutorial on interpreting pedigree
Part 3
6. What are the hallmarks of an autosomal recessive trait?
The hallmarks of autosomal recessive traits are males and females are affected in equal proportions; consanguinity is sometimes present; the disease may be seen in siblings of affected individuals but not their parents; ¼ of the offspring of carrier parents are affected; skips generations; must have 2 copies of the mutant gene to be apparent.
7. What does consanguineous mean?
Consanguineous means mating between related individuals.
8. Why is this concept especially important when discussing recessive genetic disorders?
Consanguineous is important when discussing recessive genetic disorders because it causes a higher risk of passing the recessive disease.
9. 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?
The inheritance pattern of factor viii deficiency points towards it being sex-linked rather than autosomal recessive because it is only seen in males on the pedigree.
Resources http://education-portal.com/academy/lesson/what-is-hemophilia---symptoms-genetic-cause-treatment.html ~ 7 min tutorial on hemophilia
Part 4
10. What are the characteristics of X-linked recessive inheritance?
The characteristics of X-linked recessive inheritance are the disease is never passed from father to son. Males are more likely affected than females; if affected males cannot reproduce, only males will be affected. All affected males in a family are related through their mothers. Trait or disease is typically passed from an affected grandfather, through his carrier daughters, to half of his grandsons.
11. Why does a son never inherit his father’s defective X chromosome?
A son will never inherit his father’s defective X chromosome because the son receives the Y chromosome from his father.
12. What is required for a woman to display a sex-linked recessive trait?
For a woman to display a sex-linked recessive trait, she must have two X chromosomes with the sex-linked recessive trait.
Return to the pedigree drawn earlier for Greg and Olga; mark those persons who are carriers of the factor viii deficiency gene.
13. What is the chance that Greg carries the factor viii gene?
Because Greg is not affected by factor viii gene, he is not a carrier.
14. Can he pass the gene on to his sons? His daughters? How will each be affected?
Greg cannot pass the gene onto his sons because he passes the Y chromosome not the X. Greg will pass the X chromosome onto his daughter; however, the factor viii gene will not be on it.
Resources
Human Genetics for First Year Students: X-linked Recessive Inheritance http://www.uic.edu/classes/bms/bms655/lesson7.html Part 5
15.
What are some of the risks and benefits of genetic testing as it relates to legal (not medical) issues?
Risks associated with genetic testing risk of discrimination in health insurance and employment. Also, people may experience emotional, social, or financial consequences from the test results.
Benefits of genetic testing are the results can provide answers whether they may be positive or negative.
16. 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?
Yes, an unintended consequence of genetic testing could be that people would be liable to seek medical care out of fear that they could later be denied life or health insurance.
17. What laws should be used to govern the use of genetic data of this type?
Laws of confidentiality such as HIPAA and Genetic Information Nondiscrimination Act (GINA) are laws that should be used to govern the use of genetic
data.
Resources
Mayo Foundation: Genetic Testing http://www.mayoclinic.com/health/genetic-testing/FL00076 Private Medical Information Isn’t So Private http://www.bankrate.com/brm/news/pf/20050830a1.asp References
Anderson, J. (2013). Pedigree analysis in human genetics: Inheritance patterns. Retrieved from http://education-portal.com/academy/lesson/pedigree-analysis-in-human-genetics-inheritance-patterns.html Anderson, J. (2013). Pedigree analysis in human genetics: Tutorial. Retrieved from http://education-portal.com/academy/lesson/pedigree-analysis-in-human-genetics-tutorial.html
Huether, S M., & McCance, K. L. (2012). Understanding Pathophysiology (5th ed.). St. Louis, MO: Elsevier, Inc.
National Library of Medcine. (2013, September 19). Retrieved from Genetics Home Reference: http://ghr.nlm.nih.gov/handbook/testing?show=all Tissot, R. & Kaufman, E. (unk). Humangenetics. Retrieved from http://www.uic.edu/classes/bms/bms655/lesson7.html
No, autosomal dominant disorders do not skip generations.
3. Could Greg or his mother be carriers of the gene that causes myotonic dystrophy?
No, according to the pedigree neither Grey nor his mother have the disease; therefore, neither one can be a carrier.
4. Is there a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy (md) gene?
No, there is not a possibility that Greg’s aunt or uncle is homozygous for the myotonic dystrophy. This is because Greg’s grandfather did not have the gene.
5. What is the possibility that Greg and Olga’s children could inherit the md gene?
There is no possibility that Greg and Olga’s children could inherit the md gene. This is because neither Greg nor Olga have the md …show more content…
gene.
Resources
Human Genetics for First Year Students: Pedigree Construction http://www.uic.edu/classes/bms/bms655/lesson3.html http://education-portal.com/academy/lesson/pedigree-analysis-in-human-genetics-inheritance-patterns.html ~11 min tutorial on interpreting pedigree
Part 3
6. What are the hallmarks of an autosomal recessive trait?
The hallmarks of autosomal recessive traits are males and females are affected in equal proportions; consanguinity is sometimes present; the disease may be seen in siblings of affected individuals but not their parents; ¼ of the offspring of carrier parents are affected; skips generations; must have 2 copies of the mutant gene to be apparent.
7. What does consanguineous mean?
Consanguineous means mating between related individuals.
8. Why is this concept especially important when discussing recessive genetic disorders?
Consanguineous is important when discussing recessive genetic disorders because it causes a higher risk of passing the recessive disease.
9. 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?
The inheritance pattern of factor viii deficiency points towards it being sex-linked rather than autosomal recessive because it is only seen in males on the pedigree.
Resources http://education-portal.com/academy/lesson/what-is-hemophilia---symptoms-genetic-cause-treatment.html ~ 7 min tutorial on hemophilia
Part 4
10. What are the characteristics of X-linked recessive inheritance?
The characteristics of X-linked recessive inheritance are the disease is never passed from father to son. Males are more likely affected than females; if affected males cannot reproduce, only males will be affected. All affected males in a family are related through their mothers. Trait or disease is typically passed from an affected grandfather, through his carrier daughters, to half of his grandsons.
11. Why does a son never inherit his father’s defective X chromosome?
A son will never inherit his father’s defective X chromosome because the son receives the Y chromosome from his father.
12. What is required for a woman to display a sex-linked recessive trait?
For a woman to display a sex-linked recessive trait, she must have two X chromosomes with the sex-linked recessive trait.
Return to the pedigree drawn earlier for Greg and Olga; mark those persons who are carriers of the factor viii deficiency gene.
13. What is the chance that Greg carries the factor viii gene?
Because Greg is not affected by factor viii gene, he is not a carrier.
14. Can he pass the gene on to his sons? His daughters? How will each be affected?
Greg cannot pass the gene onto his sons because he passes the Y chromosome not the X. Greg will pass the X chromosome onto his daughter; however, the factor viii gene will not be on it.
Resources
Human Genetics for First Year Students: X-linked Recessive Inheritance http://www.uic.edu/classes/bms/bms655/lesson7.html Part 5
15.
What are some of the risks and benefits of genetic testing as it relates to legal (not medical) issues?
Risks associated with genetic testing risk of discrimination in health insurance and employment. Also, people may experience emotional, social, or financial consequences from the test results.
Benefits of genetic testing are the results can provide answers whether they may be positive or negative.
16. 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?
Yes, an unintended consequence of genetic testing could be that people would be liable to seek medical care out of fear that they could later be denied life or health insurance.
17. What laws should be used to govern the use of genetic data of this type?
Laws of confidentiality such as HIPAA and Genetic Information Nondiscrimination Act (GINA) are laws that should be used to govern the use of genetic
data.
Resources
Mayo Foundation: Genetic Testing http://www.mayoclinic.com/health/genetic-testing/FL00076 Private Medical Information Isn’t So Private http://www.bankrate.com/brm/news/pf/20050830a1.asp References
Anderson, J. (2013). Pedigree analysis in human genetics: Inheritance patterns. Retrieved from http://education-portal.com/academy/lesson/pedigree-analysis-in-human-genetics-inheritance-patterns.html Anderson, J. (2013). Pedigree analysis in human genetics: Tutorial. Retrieved from http://education-portal.com/academy/lesson/pedigree-analysis-in-human-genetics-tutorial.html
Huether, S M., & McCance, K. L. (2012). Understanding Pathophysiology (5th ed.). St. Louis, MO: Elsevier, Inc.
National Library of Medcine. (2013, September 19). Retrieved from Genetics Home Reference: http://ghr.nlm.nih.gov/handbook/testing?show=all Tissot, R. & Kaufman, E. (unk). Humangenetics. Retrieved from http://www.uic.edu/classes/bms/bms655/lesson7.html