
Genetics in Practice case studies are critical-thinking exercises that allow you to apply your new knowledge of human genetics to real-life problems.
Case study
Michelle was a 42-year-old woman who had declined counselling and amniocentesis at 16 weeks of pregnancy but was referred for genetic counseling after an abnormal ultrasound at 20 weeks of gestation. After the ultrasound, a number of findings suggested a possible chromosome abnormality in the fetus. The ultrasound showed swelling under the skin at the back of the fetus’s neck; shortness of the femur, humerus, and ear length; and underdevelopment of the middle section of the fifth finger. Michelle’s physician performed an amniocentesis and referred her to the genetics program. Michelle and her husband did not want genetic counseling before receiving the results of the cytogenetic analysis.
This was Michelle’s third pregnancy; she and her husband, Mike, had a 6-year-old daughter and a 3-year-old son. At their next session, the counselor informed the couple that the results revealed trisomy 21, explored their understanding of Down syndrome, and elicited their experiences with people with disabilities. She also reviewed the clinical concerns revealed by the ultrasound and associated anomalies (mild to severe intellectual disability, cardiac defects, and kidney problems). The options available to the couple were outlined. They were provided with a booklet written for parents making choices after the prenatal diagnosis of Down syndrome. After a week of careful deliberation with their family, friends, and clergy, they elected to terminate the pregnancy.
Do you think that this couple had the right to terminate the pregnancy in light of the prenatal diagnosis? If not, under what circumstance would a couple have this right? What other options were available to the couple?

To determine: Whether to continue or terminate a pregnancy after the diagnosis of Down syndrome.
Introduction: Genetic diseases are much severe nowadays. However, diseases are hard to cure but can be controlled. Down syndrome is also one of them. In this case, the 21st pair of the chromosome has one extra chromosome. It results in health and growth defects of the child in the early stages.
Explanation of Solution
The child was diagnosed with multiple severe retardations which includes shortening of neck and fingers, and shortening of bones. The child suffers a lot after birth and has severe medical problems.
Thus, the couple has a legal right to terminate their pregnancy. However, people personally agreeing with the couple’s choice is a matter of religious, social, and cultural belief.

To describe: The conditions under which couple have the right to terminate the pregnancy.
Explanation of Solution
The couple had 20 weeks of gestation period when they decided to carry out the termination of pregnancy. According to the law, termination can be carried in between 0 to 12 weeks where the fetus is not well differentiated. In certain medical cases where the child has a severe genetic disability, the termination of pregnancy can be done after the process of diagnosis, under the guidance of doctors. The couple has the right to terminate a pregnancy where the mother’s life is affected because of the pregnancy.
Thus, the termination was not permitted by laws, but the genetic defects allowed them to terminate without any problem.

To describe: The other options that can be opted by the couple instead of termination.
Explanation of Solution
The other choices are available if the child has abnormal growth or genetic disorder other than termination of pregnancy. The fetus has already undergone severe retardation. Gene therapy is not possible because it can be used to treat only one type of gene at a time and it is applicable for certain types of genes. Medical treatment is the other option.
Hence, there are a few other options that can be opted by the couple instead of termination of pregnancy.
Want to see more full solutions like this?
Chapter 6 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
- An 1100 pound equine patient was given 20 mg/kg sucralfate 3 times a day, 2.8 mg/kg famotidine twice a day, and 10mg/kg doxycycline twice a day. Sucralfate comes as a 1 gm tablet, famotidine as 20 mg tablets, and doxycycline as 100mg tablets. All are in bottles of 100 tablets.How many total mg are needed for the patient and how many tablets of each would be needed to provide each dose?How many bottles of each would be needed to have available if this patient were to be on this drug regimen for 5 days?arrow_forwardThe patient needs a solution of 2.5% dextrose in Lactated Ringer’s solution to run at 75 ml/hr for at least the next 12hours. LRS comes in fluid bags of 500 ml, 1 Liter, 3 Liters and 5 Liters. How can a 2.5% solution be made by adding50% dextrose to the LRS?arrow_forward“Gretchen” was a 68-pound canine who came to the VMTH as small animal surgery patient. She receivedacepromazine, 0.2 mg/kg from a 10 mg/ml solution and oxymorphone, 0.08 mg/kg from a 1 mg/ml solution before surgery.What are the mechanisms of action of acepromazine and oxymorphone? Why would they be given together?How many mg provide each dose and how many ml of each of these solutions were given?arrow_forward
- After surgery, “Gretchen” was put on carprofen, 1 mg/pound bid (twice a day). The tablets come in 25, 75 and 100 mgsizes. Which size tablet would be appropriate?What is the mechanism of action of carprofen?An outpatient prescription was written for her so she would have enough for 10 days. How many tablets did she need?What information needs to be on her out-patient prescription?arrow_forwardJoden Koepp olor in chickens is due to incomplete dominance. BB = Black chicken, WW = White BLOOD TYPES Arhite chicken is In humans, Rh positive blood is dominant (R) over Rh negative blood (r). A man with type 0, Rh positive blood (whose mother had Rh negative blood), marries a woman with type AB, Rh negative blood. Several children were born. is? R R Genotypes Phenotypes RRR RR Rr Rr 4/16 RR R RR RK Rr Rr 4/16 rr 3/4 Rh posi 1/4 Rh negu 1/2 Rr rr rr rrrr 88 888 75 e genotype of the man? the genotype of the woman? The mother of the man had type AB blood.arrow_forwardPlease indentify the unknown organismarrow_forward
- 5G JA ATTC 3 3 CTIA A1G5 5 GAAT I I3 3 CTIA AA5 Fig. 5-3: The Eco restriction site (left) would be cleaved at the locations indicated by the arrows. However, a SNP in the position shown in gray (right) would prevent cleavage at this site by EcoRI One of the SNPs in B. rapa is found within the Park14 locus and can be detected by RFLP analysis. The CT polymorphism is found in the intron of the Bra013780 gene found on Chromosome 1. The Park14 allele with the "C" in the SNP has two EcoRI sites and thus is cleaved twice by EcoRI If there is a "T" in that SNP, one of the EcoRI sites is altered, so the Park14 allele with the T in the SNP has only one EcoRI site (Fig. 5-3). Park14 allele with SNP(C) Park14 allele with SNPT) 839 EcoRI 1101 EcoRI 839 EcoRI Fig. 5.4: Schematic restriction maps of the two different Park14 alleles (1316 bp long) of B. rapa. Where on these maps is the CT SNP located? 90 The primers used to amplify the DNA at the Park14 locus (see Fig. 5 and Table 3 of Slankster et…arrow_forwardFrom your previous experiment, you found that this enhancer activates stripe 2 of eve expression. When you sequence this enhancer you find several binding sites for the gap gene, Giant. To test how Giant interacts with eve, you decide to remove all of the Giant binding sites from the eve enhancer. What results do you expect to see with respect to eve expression?arrow_forwardWhat experiment could you do to see if the maternal gene, bicoid, is sufficient to form anterior fates?arrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeBiology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage LearningBiology: The Unity and Diversity of Life (MindTap...BiologyISBN:9781305073951Author:Cecie Starr, Ralph Taggart, Christine Evers, Lisa StarrPublisher:Cengage Learning



