Inherited Diseases Medical Detectives © 2013 Project Lead The Way, Inc.

DO NOW Thursday December 8th What is the name of gene responsible for HD? What is the mutation in this gene? What kind of molecule do genes code for? How does this mutation result in damage to brain cells?

PLAN Use appropriate laboratory methods to isolate DNA from cheek cells. DO Discuss Lab Conduct Lab Discuss DNA structure and inherited diseases while waiting for DNA to precipitate

DNA Isolation Lab Collect Cheek Cells Cell Lysis Precipitate DNA Initial your 15 mL tube Swish Gatorade for 1 full minute Open your tube and spit Gatorade directly into it. Cell Lysis Add 2 mL of cell lysis solution Put the cap back on your tube Invert tube carefully 5 times DO NOT SHAKE TUBE Wait 4 minutes Precipitate DNA Hold tube at an angle Add ice cold ethanol to 13-14 mL by running it down side of tube Let sit for 10 minutes in test tube rack DO NOT MOVE IT

What are the FOUR bases found in DNA? What molecule does DNA code for? What is the name for the shape of a DNA molecule? How many chromosomes does a human have? Why is DNA extraction important? While you wait…

While you wait… Discussion of Inherited diseases like Huntington’s Disease…..

Types of Inherited Diseases Recessive Requires a mutated copy of the gene from each parent for child to have the disease.

Types of Inherited Diseases Dominant Requires a mutated copy of the gene from only one parent for the child to have the disease.

Examples of Inherited Diseases Tay Sachs-recessive (both parents must pass) Hemophilia-recessive (both parents must pass) Cystic Fibrosis-recessive (both parents must pass) Huntington’s Disease-dominant (only one parent must pass) Polycystic Kidney Disease-dominant (only one parent must pass) Hemachromatosis-recessive (both parents must pass) Sickle Cell Anemia-recessive (both parents must pass)

Cystic Fibrosis What is it? A recessive genetic disease caused by the production of abnormal, thick, sticky mucus. What is the outcome? Death caused by lung infections usually before age 35. What are the symptoms? Coughing and wheezing Diarrhea Chronic lung infections

Huntington’s Disease What is it? A dominant genetic disease caused by the deterioration of nerve cells in the brain. What is the outcome? Continual decline in mental and physical ability; death usually occurs 15 to 20 years after onset. What are the symptoms? Difficulty walking Uncontrollable body movements Memory and cognitive impairment

What Causes Inherited Diseases? Genetic material of a cell is changed (called a mutation), causing a change in the cells and ultimately the body’s function which lead to a disease. The genetic material is deoxyribonucleic acid (DNA) and contains the instructions for the growth and development of the individual. The changed genetic material is passed from parent to child.

While you wait….. Now answer Conclusion questions 9-11 on page 33-34 of your biomedical science journal. If time permits, go ahead and cut the string for your DNA necklace (30 inches long). Tie the ends of the string together to form a loop. Make sure the loop will fit over your head.

Making your DNA Necklace Use a plastic pipet to draw the DNA (white strands) out of the ethanol layer (top layer) in your tube. Expel the DNA out of the pipet into your pendant tube. Fill the rest of the tube with ethanol ONE DROP AT A TIME. Do not overfill. Place your loop of string around the hinge of the cap on your pendant tube and close the cap. Put on your necklace and invert the tube to watch your DNA move through the ethanol. ENJOY!!

Image Resources By Français : Domaina [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons By Kashmiri, based on earlier work by Domaina [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons By KES47 (File:Chromosome zh.svg) [CC-BY-3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons