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6th Grade Science / Lesson 12 - Inherited Diseases

Diseases Inherited
What will we be learning today?

  • In this lesson, we are going to learn all about what kind of diseases are inherited.

What Kinds of Diseases Are Inherited?

  • Sickle cell anemia is not a disease you can "catch" from someone else, like a cold or sore throat. It is a genetic disorder, because it is caused by the combination of genes an individual inherited from his or her parents.


  • Hemophilia is an inherited disease. People who have hemophilia have blood that does not clot properly. Small cuts can cause severe bleeding. Hemophiliacs can also suffer from internal bleeding. Like color blindness hemophilia is a recessive, sex-linked trait. As a result the disease is more common in males.

Other Genetic Diseases and Disorders

  • Sickle cell anemia, dyslexia, cystic fibrosis, Down syndrome, and PKU are genetic disorders that are not sex linked.

Dyslexia is a genetic disorder that is sometimes called word blindness. People who have dyslexia may have trouble reading and writing because they see some letters and words backward. Special teaching methods help these children overcome the problems presented by dyslexia.

Cystic fibrosis is a genetic disorder that causes the buildup of too much thick, sticky mucus in the lungs and other organs. Children with cystic fibrosis have difficulty breathing, which means they may have trouble participating in sports and many other forms of exercise. These children also have trouble digesting food, so they are often kept on special diets. Children with cystic fibrosis do special breathing exercises and receive other kinds of treatment, including physical therapy.

Daily physical therapy treatments help to loosen the thick coating of mucus in the lungs of a child who has cystic fibrosis. Cystic fibrosis is the most common genetic disorder in Caucasians.

Down syndrome is a genetic disorder that occurs when a child inherits an extra copy of a specific chromosome. Scientists are studying the genes carried by chromosome number 21 to find out why having an extra copy causes Down syndrome. People with Down syndrome may have severe mental retardation. They may also have problems with their heart, eyes, or intestines. However, many people with Down syndrome may lead active, productive lives.

Another inherited disease is PKU. This is short for phenylketonuria. This disease affects the nervous system. The body cannot break down a certain substance. The substance builds up and can cause brain damage. This disease can be treated if the treatment starts soon after a child is born. There is a test for PKU for newborns.

Let's Review What We Learned Today!

  • Now complete your worksheet!