1. Karyotypes and Pedigrees
Genetics and Chromosomal Analysis
Karyotypes and Pedigrees

2. Chromosomal Analysis There are various ways to analyze chromosomes:
1. Karyotypes
2. Chromosome painting
3. Gel electrophoresis (DNA fingerprinting)

3. Chromosome painting: using fluorescents to compare chromosomes

4. Gel Electrophoresis: separating DNA according to their molecular size

5. Karyotype- a chart of chromosomes pairs

6. Male Karyotype

8. Any individual with at least one Y chromosome is male and without one Y is female.
XX- Female
XY –Male

9. Down Syndrome (trisomy-21)
Autosomal nondisjunction
affected individuals survive to adulthood
It occurs in about 1 and 700 live births

10. - There is a third chromosome on the 21st pair.
- They have varying degrees of mental disability.
- The incidence is higher among older mothers, especially those over 40.

12. Characteristics: short, slanted eyes, thick tongue

13. SEX CHROMOSOME NONDISJUNCTION – Unusual numbers of sex chromosomes

14. One X chromosome is missing
Turner’s Syndrome XO
One X chromosome is missing
FEMALES ONLY!
Monosomy X – gets only
ONE X chromosome
Sterile female
Low intelligence
No breasts (no secondary sex characteristics)

16. Klinefelter syndrome XXY Extra X chromosome MALES ONLY!
causes a male to be sterile
No beard, no deep voice, no masculine muscle tone (no secondary sex characteristics)

17. Most of these individuals lead normal lives, but they can not have children and some may have some degree of mental retardation.

19. Superman Syndrome XYY Male Has an extra Y chromosome
On average 3” taller than your average male
Clinical phenotype of this syndrome is normal

21. RECESSIVE AUTOSOMAL DISORDERS-Deals with chromosome pairs #1-22

22. Cystic Fibrosis Excess mucus in lungs
Mostly found in Caucasian population
Chromosome #7

23. Phenylketonuria (PKU)
Lack of normal skin pigmentation
Mental retardation
Can prevent with special diet
Chromosome #12
Absence of certain enzyme
Damage to Central Nervous System

25. Tay-Sachs Disease Lipids (fats) in brain cells
Affects Central Nervous System
Mental deficiency
Fatal, usually causes death by
age 2
Mostly in Jewish population
Chromosome #15

26. DOMINANT AUTOSOMAL DISORDERS - Deals with chromosome pairs #1-22

27. Huntington’s Disease Chromosome #4 Memory loss Uncontrolled movements
Onset occurs between the ages of (middle age)
Forgets things, stumbles
Cause: abnormal repeating of certain bases

28. CODOMINANT AUTOSOMAL DISORDERS

29. Sickle Cell Anemia Sickle-shaped red blood cells Difficulty breathing
Nitrogen base is changed, affects HEMOGLOBIN that carries oxygen
Mostly in African Americans
Cells clot
Capillaries are cut causing bleeding internally.
Chromosome #11

30. Pedigree- a graphic representation of genetic inheritance from generation to generation

31. Pedigree Symbols Normal female Affected female Carrier/heterozygous female Normal male Affected male Carrier/heterozygous male Death Married Parent and Offspring

32. A carrier is represented by a half shaded circle or square
A carrier is represented by a half shaded circle or square. They are heterozygous- they have a recessive gene but it does not show.

34. DNA FINGERPRINTING
aka
GEL ELECTROPHORESIS

35. Why ?? To determine whether suspects have been at a crime scene/location
Who?? Law enforcement

36. How does it work???
Small DNA samples can be obtained from blood, hair, skin, and copied millions of times.
The DNA is cut into fragments of different lengths
DNA fragments can then be separated by electrophoresis, and compared with those obtained from a crime scene

38. The genes follow standard patterns from person to person
BUT the non-coding segments produce distinct combinations of patterns that are unique to each individual
SO unique fingerprints can be used to identify a single person.

39. No two people have the same DNA (except identical twins)