1. Genetic Disorders & Diseases

2. Genetic Disorders/diseases
Genetic disorders/diseases are caused by mutations.
A mutation is any type of change in genetic material.
Mutations are caused by:
Radiation
X-rays, sun exposure
Chemicals
May contain toxic substances

3. Mutations
You can pass on mutations to your offspring only if the mutation is in your sex cells!!

4. Mutations
Mutations in your body cells can be passed on to other cells of your body only!!
Cancer (not inherited)

5. Types of Mutations
Whole chromosomes are missing OR there are extra chromosomes.
This is caused by disjunction which happens during meiosis when chromosomes did not segregate or separate and distribute to the gametes properly.
Examples:
Trisomy 13
Trisomy 21
Turner’s Syndrome
Kleinfelter’s Syndrome

6. Trisomy 21 – Down’s Syndrome
Extra copy of chromosome 21
The incidence of Down syndrome is estimated at 1 per 800 to 1,000 births, although these statistics are heavily influenced by the age of the mother.

7. Trisomy 13
Chromosomal condition that is associated with severe mental retardation and certain physical abnormalities.
small eyes that may exhibit a split in the iris
an opening in the roof of the mouth (a cleft palate) and/or a cleft lip,
weak muscle tone
skeletal abnormalities,
Affected individuals rarely live past infancy because of the life-threatening medical problems associated with this condition
Trisomy 13 affects approximately 1 in 10,000 newborns. The risk of having a child with trisomy 13 increases as a woman gets older.

8. Turner’s Syndrome One sex chromosome
Underdeveloped sex characteristics
One in 2500 births

9. Kleinfelter’s Syndrome
2 XX’s 1 Y
Underdeveloped sex organs

10. Types of Mutations
2. Sections of Chromosomes are missing or misplaced.
Inversion mutation
Duplication
Deletion

11. Sections of Chromosomes are missing or misplaced con’t…
Translocation

12. Genetic Disorders
Genetic Disorders can also be caused by recessive defective alleles:
Each parent carries 1 recessive allele. Offspring may inherit the defective allele from both parents and get the disease.
Sickle cell
Phenylketonuria
Tay-Sachs
Cystic Fibrosis
Huntington’s Disease

13. Sickle Cell
Your Genes, Your Health

14. Phenylketonuria - PKU Most children are screened at birth for PKU
Can lead to mental retardation
Smaller than normal head
Epilepsy
Deficiency in the enzyme phenylalanine hydroxylase (PAH). This enzyme is necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine

15. Tay-Sachs Disease
Your Genes, Your Health

16. Cystic Fibrosis & Huntington’s Disease
Huntington's Disease – dominant disease, you need to inherit only 1 copy of the disease to have it. Abnormal protein is produced and you start to kill brain tissue occurs around middle age, mood swings, paralysis, loss of memory, uncontrolled movements and eventually death
1 in 20,000 in western hemisphere, 1 in 1 million in Asia
Cystic Fibrosis – recessive disorder, a genetic mutation stops the production on a protein of cells in the lung, pancreas or other organ
Affects about 1 on 2500 births in the US