Effects of DNA Mutations in Sex Cells… Genetic Disease or Birth Defects

EFFECTS IN SEX CELLS A DNA mutation that occurs in sex cells can be passed down to children through egg and sperm cells. It can lead to birth defects or genetic disorders. GENETIC DISORDERS Sickle Cell Anemia BIRTH DEFECTS Aperts Treacher-Collins Progeria FOP

Sickle Cell Anemia Cause Sickle cell anemia is caused by a mutation in a gene located on chromosome 11. The code causes one amino acid to be replaced with another as the protein hemoglobin is made. Now complete the transcription/translation activity in the workbook to discover the name of the amino acid that is different in sickle cell anemia Effects The changed amino acid causes the hemoglobin to change shape. As a result, the normally rounded red blood cell is distorted into a sickle shape (curved with pointed ends). The deformed cell is abnormally fragile, rupturing easily and clogging the vessels. As the red cells break down at an increased rate, the body experiences anemia. The anemic person becomes weak, dizzy, and short of breath during physical exertion. Also, as capillaries all over the body become blocked by clumped sickle cells, body organs are damaged, leading to pain and often premature death.

Aperts Syndrome Click the graphic to see other photos Cause Caused by a mutation in the gene called growth factor receptor 2. It may be inherited as a dominant gene OR it may occur as a spontaneous mutation (which means it’s not linked to heredity. Effects Causes premature closure of the skull resulting in a peaked head and unusual facial appearance. There may be webbing between fingers and toes. Bones in hands and feet become fused resulting in less flexibility and function.

Treacher-Collins Syndrome Cause This syndrome is caused by a defective gene called treacle. It can be inherited as a dominant trait, however, 50% are spontaneous mutations. Effects Results in abnormal ear structure, small jaw with a large mouth and a defect in the lower eyelid. Scalp hair extends onto cheeks. People with this syndrome do have normal intelligence Click the graphic to see another photo

Progeria Cause Exact cause unknown Effects Progeria causes growth failure. Little children appear to be old people. They are bald and have early artherosclerosis. The average lifespan is in the early teens

Fibrodysplasia Ossificans Progressiva (FOP) Click the picture to see more photos Cause Genetic mutation in the gene that turns on after birth to form extra bone. Caused by a mutation. It is not inherited The gene is on chromosome 4. Effects Children appear normal at birth. Bone forms in muscles, tendons and ligaments. Extra bone progressively restricts movement. Individuals start growing bone all over the body between ages of This bone replaces the muscles.