1. GENETIC DISORDERS

2. A genetic disorder is a disease that is caused by an abnormality in an individual's DNA.
Abnormalities can range from a small mutation in a single gene to the addition or subtraction of an entire chromosome or set of chromosomes.

3. Gene Mutations Can either be inherited from a parent or acquired
Failure of chromosome pairs to separate properly is called NON-DISJUNCTION
Non-disjunction will result in an imbalance of chromosomes
Having more or less genetic material is detrimental and is the resulting cause of Genetic Disorders

4. There are four major types of chromosomal mutations:

5. #1 DELETIONS:
involve deletion of a small portion of a chromosome

6. #2 DUPLICATIONS:
produces an extra exact copy of a specific region of a specific chromosome

7. #3 INVERSIONS:
re-order a segment of chromosome in backwards order
Not as detrimental as deletion or insertion

8. #4 – TRANSLOCATIONS:
Occurs when the information from one of two homologous chromosomes breaks and binds to the other
Usually this sort of mutation is lethal

9. In humans, non-disjunction is most often associated with the 21st chromosome, producing a disease known as Down's syndrome (also referred to as trisomy 21).

10. Sufferers of Down's syndrome display the
following characteristics:
mild to severe mental retardation
short stocky body type
Upward slant to the eyes
large tongue leading to speech difficulties

11. Kleinfelter’s Syndrome
Males with Kleinfelter’s have an extra X chromosome (XXY)
Infertile – do not produce sperm
Enlarged breasts
Small penis and testicles
Sparse facial and body hair

14. Turner’s Syndrome
Missing or damaged X chromosome in females (Momosomy X)
Underdeveloped ovaries
Short stature, webbed neck
Sterile
Lacking secondary sexual characteristics

16. Cystic Fibrosis
Hereditary disease primarily affecting the lungs, pancreas and intestines
Caused by faulty channel proteins
Excess mucous clogs lungs causing a difficulty in breathing, prevents food from being digested
Diagnosed with a “sweat test”
Life expectancy of patients ~ 36 years

18. Duchenne’s Muscular Dystrophy
Generalized weakness and muscle wasting first affecting hips, pelvic area, thighs and shoulders
X linked recessive disorder
Eventually even muscles of the lung may weaken which may lead to respiratory failure

20. Albinism
Characterized by little or no pigment in the eyes, skin and hair
Major vision problems
Inherited altered genes do not make usual amounts of pigment melanin
Both parents must carry a defective OCA (oculocutaneous albinism) gene to have a child with albinism

22. Red-Green Colour Blindness
X-linked recessive disorder
Person cannot distinguish shades of red and green
Visual acuity is normal

23. Progeria A rare disorder in where a person ages rapidly.
Caused by random, spontaneous mutation of one gene.
The mutated gene must be dominant over it’s recessive normal partner.
It is an autosomal disorder.

24. Progeria – Physical features.

25. Phenylketonuria or PKU
People with PKU cannot consume any product that contains aspartame.
PKU is a metabolic disorder that results when the PKU gene is inherited from both parents (autosomal recessive disorder)
Caused by a deficiency of an enzyme which is necessary for proper metabolism of an amino acid called phenylalanine.

26. PKU
Phenylalanine is an essential amino acid and is found in nearly all foods which contain protein, dairy products, nuts, beans, tofu… etc.
A low protein diet must be followed.
Brain damage can result if the diet is not followed causing mental retardation…and mousy body odor (phenylacetic acid is in sweat).

27. PKU

28. Phenylalanine. Free diet