1. Human Genetic Disorders Notes

2. What causes genetic disorders? Mutations, or changes in a person’s DNA

3. Cystic Fibrosis A genetic disorder in which the body produces abnormally thick mucus in the lungs and intestines.

4. Sickle-Cell Disease A genetic disorder that affects the blood Caused by a mutation that affects the production of an important protein called hemoglobin Hemoglobin is the protein in red blood cells that carries oxygen People with disease suffer from lack of oxygen in the blood and experience pain and weakness

5. Hemophilia Genetic disorder in which a person’s blood clots very slowly or not at all People with disorder do not produce one of the proteins needed for normal blood clotting Disorder that is carried on the recessive allele on the X chromosome (sex-linked gene) More common in males than females

6. Huntington’s Disease Genetic disorder that is caused by a dominant allele Every individual who inherits the allele develops the disease A person with the disease has a 50% chance of passing it on Fatal; symptoms do not usually appear until a person is over 30 years old Causes the gradual breakdown of cells in the brain

7. Down Syndrome Genetic disorder that is the result of an extra copy of chromosome 21 Result of an error during meiosis-chromosomes failing to separate People with Downs have a distinctive physical appearance and have some degree of mental retardation; heart defects are also common

8. Karyotype of a Female with Down Syndrome Notice the extra chromosome

9. Genetic Tools Karyotype Picture of all the homologous chromosomes in a cell Amniocentesis A procedure in which fluid surrounding a developing baby is removed Needle

10. Diagnosing Genetic Disorders Today doctors use tools such as amniocentesis and karyotypes to help detect genetic disorders