Arthur joined the track team recently, but had to quit abruptly due to sudden pains in his joints. He wants to figure out what might be causing these pains and finds out that he is a carrier for sickle cell, which runs in his biological family. This storyline addresses the reasons why some diseases seem to affect certain races or ethnicities more than others.
MS-LS3-1. Develop and use a model to describe why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism.
Sickle Cell Anemia; mutation, genes, inheritance
This storyline concerns inherited illnesses and encourages students to explore why some genetic illnesses are more prevalent in certain ethnic groups.
Arthur's aches and pains have made him concerned about his health. After examining Arthur's blood, students notice some odd-shaped red blood cells.
Students help Arthur look into his family history to see where these sickled cells may have come from. Sure enough, the sickle cell gene is present in Arthur's family. Students learn that while sickle cell anemia requires two sickle cell alleles to present all of its symptoms, people who have only one allele--carriers--can still experience sickle cell symptoms under certain circumstances.
Students compare areas of the world that experience high rates of malaria with areas of the world where sickle cell is most common, and learn that sickle cell carriership actually provides partial immunity against this even deadlier disease. Students also learn that this phenomenon isn't confined to Sub-Saharan Africa; cystic fibrosis, which is most commonly seen in Caucasians, may have risen to prominence in response to the European tuberculosis epidemics of the 1800s.
