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Sonic Hedgehog

Genetic Abnormalities and Tissue Donations


Lauren E. Yaich
Division of Biological and Health Sciences
University of Pittsburgh at Bradford


In this case study about a baby born with the genetic condition holoprosencephaly, students explore the “Sonic hedgehog” gene, signal transduction, and the ethics of body and tissue donation. The assignment involves students writing an informed consent document that explains the science behind this congenital abnormality. Designed for an upper-level undergraduate biology course, the case could also be used in a cell biology, developmental biology, neurobiology, or other related upper-level course.


  • Discuss signal-transduction pathways and how they are involved in developmental events.
  • Discuss early braindevelopment and how defects in cellular signaling pathways can result in serious congenital abnormalities, such as holoprosencephaly.
  • Speculate upon ways that scientists might one day be able to detect or treat congenital abnormalities such as holoprosencephaly.
  • Discuss ethical and legal issues concerning tissue and cadaver donation for scientific research.


Holoprosencephaly; Sonic hedgehog; Cyclops; brain development; signal transduction; cell signaling; birth defect; congenital defect; tissue donation; organ donation; medical research; bioethics

Topical Areas

Ethics, Legal issues, Social issues

Educational Level

Undergraduate upper division



Type / Methods

Discussion, Role-Play



Subject Headings

Cell Biology  |   Neuroscience  |   Genetics / Heredity  |   Developmental Biology  |  

Date Posted


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