1. Genetic Disorders – Gene Disorders

2. What is a gene? Gene – Sequence of DNA bases that code for a trait (blueprint)

3. Where are genes stored? Genes are found on chromosomes. Each chromosome has its own set of genes.

4. Notable genes on Chromosome 18: Parkinson DiseaseSome types of cancer Some forms of obesity

5. Notable genes on Chromosome 20: Breast CancerDiabetes Epilepsy

6. Notable genes on Chromosome Y: InfertilityNight blindness Inability to make testes

7. How does DNA sequence lead to a trait? In order to make a trait, a cell uses the gene information to build a protein. GENEPROTEIN

8. What are some examples of proteins? -Hair -Fingernails, horns, antlers - Hemoglobin - Enzymes to digest food - Antibodies to fight disease

9. What happens if the gene is changed? As with a blueprint, if you change the directions you change the product.

10. What happens if the gene is changed? Mutation – Change in a DNA sequence – missing base – extra base – substitute a base ACTATGG ACTTGG ACTATGG ACTAGTGG ACTATGG ACTCTGG

11. Mutations Part 2 Everyone has a complete set of genes (eye color, blood type, tongue rolling, etc.) but which version you inherited makes a big difference. In reality there is no “cancer gene”. Instead, there are versions of checkpoint protein genes that don’t control cell cycle properly.

12. Notable genes on Chromosome 18: Some forms of obesity X How food is absorbed

13. Notable genes on Chromosome 20: Diabetes X Insulin to control blood sugar

14. Basic Gene Disorder Questions 1.What type of genetics is it? (Dominant, recessive, sex-linked, etc.?) 2. What gene is involved? 3. On what chromosome is this gene?

15. 4. What protein does this gene make? 5. What is this protein supposed to do? 6. Since this protein isn’t working right, how does this lead to the symptoms? Basic Gene Disorder Questions

16. Gene Disorder Example Tay Sachs 1.What type of genetics is it? (Dominant, recessive, sex-linked, etc.?) recessive 2. What gene is involved? HexA gene

17. Gene Disorder Example Tay Sachs Chromosome 15 3. On what chromosome is this gene? P’s and Q’s? -Different ends of chromosome -#’s show distance from centromere

18. Gene Disorder Example Tay Sachs 4. What protein does this gene make? Part of hexosaminidase

19. 5. What is this protein supposed to do? A. Found in lysosomes of brain and spinal cord cells B. Digests fats called gangliosides Gene Disorder Example Tay Sachs

20. 6. Since this protein isn’t working right, how does this lead to the symptoms? A. Hexosaminidase can’t break down gangliosides. B. Gangliosides build up to toxic levels. Gene Disorder Example Tay Sachs C. Nerve cells die.