1. Genetic Disorders
Unit 5

2. What is a Karotype?
A picture of the collection of chromosomes found in an individual’s cells
Tells you the chromosome number of an organism
46 in humans
Tells you the sex of an organism
XX = Female XY = Male
Can indicate whether or not a chromosomal abnormality is present.

3. Karyotype
MALE
FEMALE

4. Chromosomal Mutations
Inversion
A segment of a chromosome breaks off, flips, and reattaches
Duplication
An entire gene segment is repeated
Non Disjunction
Caused by the failure of chromosomes separating during meiosis
Typically classified as either monosomy or trisomy.
Translocation
When a section of one chromosome attaches to another chromosome
Deletion
When a section of a chromosome is deleted

5. Common Chromosomal Abnormalities
Monosomy
Trisomy
the condition in which a diploid cell is missing a chromosome
the condition in which a diploid cell has an extra chromosome

6. Down Syndrome Down Syndrome/Trisomy 21 Extra 21st Chromosome
Trisomy /Normally a non disjunction, can be a translocation.
Symptoms:
Distinctive shaped eyes
Cognitive heart abnormalities
Simian folds
Below average cognitive ability

7. Down Syndrome Down’s caused by a translocation.
Down’s caused by a non disjunction

8. Turner’s Syndrome 1 X chromosome and no match (XO) Monosomy
Turner’s Symdrome
1 X chromosome and no match (XO)
Monosomy
Only females
Symptoms
Short stature, Webbed neck, Broad chest, Non-functioning ovaries, sterility

9. Klienfelter’s Syndrome
2 X chromosomes and 1 Y
Trisomy (XXY)
Only in males
Symptoms
Underdeveloped male sex characteristics
Reduced fertility
Slightly feminime characteristics
Potential language impariment

10. Edward’s Syndrome Edward’s Syndrome/Trisomy 18
Caused by non-disjunction (trisomy)of the 18th chromosome.
Symptoms:
Clenched hands
Feet with a rounded bottom
Low birth weight
Mental delay
Poorly developed fingernails
Small head (microcephaly)

12. Cri du chat
Cri du chat
Also called “call of the cat”, chromosome 5p deletion syndrome or Lejeune’s syndrome.
Caused by a deletion of part of chromosome 5
1:50,000 live births, slightly more common in girls.
Symptoms:
Cognitive delays, unique facial features, unique cry

13. Common Gene Mutation Not detectable on a karyotype Sickle Cell Anemia
Tay-Sachs Disease
Cystic Fibrosis

14. Sickle Cell Anemia Sickle Cell
Caused by a point mutation within the protein that makes hemoglobin.
Thought to have evolved as a defense against malaria
Symptoms:
Anemia, Fatigue, Infection

15. Tay Sachs Disease
Tay Sachs Disease
Point mutation causing the body to lack a critical protein that breaks down chemicals in nerve tissue
Symptoms
Deafness, Blindness, Seizures, Demintia
No treatments
Children usually die before age 5

16. Cystic Fibrosis Cystic Fibrosis
Most common mutation is a deletion (frame shift mutation) of 3 nucleotides on chromosome 7 resulting in the loss of the amino acid phenylalanine
Symptoms
Thick mucus secretions, and frequent chest infections, trouble digesting food.