1. Mutations Affecting Humans
Genetic Diseases

2. Genetic Disorders
Thousands of genetic disorders are inherited as simple recessive traits
from benign conditions to deadly diseases
albinism
cystic fibrosis
Tay sachs
sickle cell anemia
PKU

3. Albino People

4. Albinism Occurs in Animals

5. Chromosomal Mutations Deletion in Chromosome 5

6. Cystic Fibrosis
A defective gene on chromosome 7 (resulting from the deletion of only 3 bases) is inherited as a recessive trait. The main effect seems to be the body’s excessive production of an abnormally thick and sticky mucus. This kind of mucus can block the trachea which can lead to severe breathing issues and can cause bacterial infections in the lungs. The long-term buildup of the mucus and lung infections can lead to permanent lung damage such as; the formation of scar tissue, and the growth of cysts.

8. Sickle Cell Anemia Substitution of one amino acid in polypeptide chain
hydrophilic amino acid
hydrophobic amino acid 8

9. Sickle Cell Anemia Autosomal recessive
Found most often among people of African ancestry
Blood cells sickle (change shape) when oxygen-deprived (exertion, increase in altitude) and block tiny capillaries
Causes sickle cell event – pain and immobility
and death of tissue ( dangerous if in organ)
Treatment – hospitalization and oxygen
Carriers are resistant to malaria

10. Tay Sachs Disease Single defective enzyme
Heterozygote carriers (Hh) do not have disorder, but are resistant to Tuberculosis
Fatty substance builds up in neurons
Gradual paralysis and loss of nervous function by age 4-5
Especially common in Jewish population (central and eastern European descent), up to 11% are carriers

11. Huntington Disease Autosomal dominant
Symptoms do not appear until age
Death takes about 5-10 years
No treatment, no cure – but there is a test to see if you have it before symptoms begin
Results in mental impairment and uncontrollable spastic movements

12. PKU (Phenylketonuria)
Can’t break down amino acid phenylalanine (missing critical enzyme)
Phenylalanine builds up and interferes with nervous system leading to mental retardation and even death
Early screening (urine test)  phenylalanine restricted diet for children with disorder

13. Down’s Syndrome Karyotype

14. Down’s Syndrome Trisomy 21

15. Klinefelter’s Syndrome XXY

16. Turner’s Syndrome Karyotype

17. Turner’s Syndrome

18. These disorders result from NONDISJUNCTION
Failure of chromosomes to separate normally during meiosis –
Eggs or sperm get one too many chromosomes or one too few.
Ex – Down syndrome has one extra #21
Klinefelter has one extra X chromosome
Turner has one too few – only one X

19. Polydactyly

20. The Wolf Boy (Danny Gomez) Hypertrichosis

21. Genetic Testing Amniocentesis and Chorionic Villus Sampling
Sample of amniotic fluid or placenta
Karyotyping
Taking a picture of the chromosomes in a cell