
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.
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Chapter 6 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
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