1. Human Genetic Disorders
Mrs. Wharton’s Science Class

2. What is Genetic Disorder?
A genetic disorder is an abnormal condition that a person inherits through genes or chromosomes.
Some genetic disorders are caused by mutations in the DNA of genes
Other disorders are caused by changes in the overall structure or number of chromosomes.

3. Cystic Fibrosis
Occurs when the body produces an abnormally thick mucus in the lungs and in the intestines. It makes it hard to breathe and digest food.
Caused by a recessive allele
There is no cure but there are treatments to help control the symptoms

4. Sickle Cell Disease
Affects the hemoglobin , the protein in the blood that carries oxygen
People with sickle cell suffer from lack of oxygen in the blood and experience pain and weakness
The allele that carries sickle cell is codominant with the normal allele.
There is no cure but there are medications to lesson the pain and other symtoms.

5. Hemophilia When the blood clots very slowly or not at all.
People with this disorder do not produce one of the proteins needed for blood to clot normally
Caused by a recessive allele on the X chromosome therefore occurs more often in males
With treatment people with hemophilia can lead normal lives

6. Down Syndrome
A genetic disorder when there is an extra copy of chromosome 21
Occurs when a chromosome fails to separate correctly during meiosis
People with down syndrome have distinctive physical appearance and some mental retardation.
Many people with down syndrome lead normal active lives.

7. Studying Family Trees Geneticist- one who studies genetics
Pedigree- a tool a geneticist uses to follow the passing of certain traits from generation to generation.
Karyotype- picture of all of the chromosomes.
Genetic counselor- a person who uses pedigrees, punnett squares, and karyotypes to determine the likelihood of a certain trait or genetic disorder to be passed on from generation to generation.