Pedigree

Used to show how a particular trait is passed from one generation to the

next in a family

Allelic Disorders -genetic disorders are USUALLY recessive

Albinism• Many forms, many genes

code for it• Lack of pigment in skin,

hair, and eyes.• Approx. 1 in 17,000 people

• Health Impacts1. Eye problems2. Severe sensitivity to

sunburn.

Cystic Fibrosis• Gene mutation on

chromosome 7• Health: build up of

mucus in the lungs, pneumonia• One of the first

disorders to be actively studied for gene therapy.

Sickle Cell Anemia• Codominant disorder

found in African Americans.

• Red blood cells are mishapen.

• Characterized by extreme pain in legs and arms because the cells get stuck in capillaries.

Tay-SachsFatal genetic disorder from a buildup of fatty substances in tissues and nerve cells in brain.

Infants develop normally then deteriorate to become blind, deaf, unable to swallow leading to muscle atrophy and paralysis.

Persons with Tay-Sachs also have "cherry-red" spots in their eyes.

Both parents must carry the mutated gene in order to have an affected child.

Huntington’s Disease

• Results in a loss of muscle control and mental function. The symptoms usually do not appear until after 30 years old.

• Approximately 1 in 10,000 births• Gene on chromosome 4

Huntington’s Disease

Color Blindness

• Recessive gene located on the X chromosome.• Sex-Linked disorder• Cannot distinguish red/green• Does color blindness affect more men or

women? MEN• Why? Men only have one X chromosome, thus

only one copy of the color blind gene.

Hemophilia

• A disorder in which a person’s blood does not clot properly.

• Gene found on X chromosome.

• 1 in 10,000 males born are afflicted.

Pedigree Chart and Symbols