1. Genetic Disorders

2. Crossing Over…

4. What happens when there is a mistake???
When there is a mistake in Anaphase, chromosomes do not separate correctly. This is called NON-DISJUNCTION.
This can lead to a Monosomy (45) or a trisomy (47) where there are incorrect numbers of chromosomes in a person’s Karyotype.

5. Mutations
Non-Disjunction Disorders are caused when there is a mistake during Meiosis that causes the homologous chromosomes to fail to separate.

6. So how do we tell there is a problem?
Amniocentesis is a procedure that checks for these abnormalities in embryos. A small sample of amniotic fluid is drawn and used to detect chromosomal aneuploidies.

7. Autosomal Sex-Linked Aneuploidies
Genetic Diseases
Autosomal
Sex-Linked
Aneuploidies

8. Cystic Fibrosis
Missing the enzyme to break down mucous in the lungs and digestive tract
Very hard to breathe
Most common in Caucasians
Life expectancy has increased with enzyme injections and gene therapy

9. Sickle Cell Anemia
Red blood cells form a sickle shape when they don’t get enough oxygen (during exercise or activity)
Red blood cells that are sickled get stuck in the blood vessels and cause joint pain and muscle weakness
Difficulties breathing
Most common in African race

10. Tay Sachs Disease Build up of fatty acids on the brain
Causes death by the age of 5
Blindness, inability to walk, crawl, etc.
Common among Ashkenazi Jewish populations

11. Phenylketonuria (PKU)
All babies are tested at birth
Missing the enzyme to break down phenylalanine (an amino acid found in milk and artificial sweetners)
Can live normal life with a modified diet

12. Huntington’s Disease Caused by a dominant allele
Does not appear until the age of 30-50
Causes breakdown of brain areas controlling motor functions
Severe shaking and eventually death

13. Hemophilia Sex-linked disease Inability to clot blood
Can receive blood transfusions with factor VIII (clotting factor)
Known as Queen Victoria’s disease

14. Colorblindness Sex-linked recessive
Inability to distinguish between red and green colors
No treatment

15. Down’s syndrome Autosomal aneuploidy Three chromosome 21’s
Mental retardation, heart problems
Characteristic facial features

16. Turner’s Syndrome Sex chromosome aneuploidy
Female with only one X chromosome
Short stature, webbed neck
No ovaries
Slight mental retardation possible
This type of aneuploidy is called monosomy

17. Kleinfelter’s Syndrome
Sex chromosome aneuploidy
Male with an extra X chromosome
so he has XXY genotype
Feminine characteristics
Slight mental retardation
Sterile
This type of aneuploidy is called trisomy