In Sickness and in Health
A Trip to the Genetic Counselor
Natural Sciences Division
Pasadena City College
In this interrupted case study, Greg and Olga, a young couple planning a family, have decided to see a genetic counselor because of a family history of genetic disease. Students construct a pedigree from the information presented in the case; then, on the basis of that, determine if the couple are carriers for any recessive genetic diseases and the likelihood of their passing those diseases on to their children. Students learn about the inheritance of single gene dominant, recessive, and sex-linked disorders as well as the significance of carrier frequency. Originally developed for use in a non-science major general biology course, the case has also been used in a human genetics course for non-science majors.
- Construct a pedigree from a written narrative.
- Be able to determine, from a pedigree, carriers of recessive genetic diseases and the probability that they will pass those diseases on to their offspring.
- Understand the rules governing the inheritance of single gene dominant, recessive, and sex-linked disorders and be able to apply them to analyze simple genetics problems.
- Be able to determine the carrier frequency of a trait given the prevalence of the trait in the population, as well as understand the significance of carrier frequency.
KeywordsGenetic counseling; chromosome; homozygous; heterozygous; allele; pedigree; autosomal inheritance; sex-linked inheritance; population genetics; myotonic dystrophy; Hardy-Weinberg; dominant; recessive; genetic disease
Educational LevelHigh school, Undergraduate lower division
Type / MethodsInterrupted
Subject HeadingsBiology (General) | Genetics / Heredity |
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