Karyotyping is used to identify chromosomal disorders by staining and organizing chromosomes from longest to shortest based on banding pattern. Abnormalities include an extra chromosome like Trisomy 21 which causes Down Syndrome characteristics such as cognitive impairment and heart defects, or a missing sex chromosome as in Turner's Syndrome where females are sterile with short stature.

1. BIOLOGY
Unit 4 Notes:
Karyotyping

2. • Purpose:
To look at chromosome pairs to identify
chromosomal-disorders.
• Process:
1. Stain DNA.
2. Organize longest  shortest.
3. Organize by banding pattern.
4. Sex chromosomes at the end.
5. Look for too many, missing, shortened, or
lengthened chromosomes.
(1) Karyotyping:

3. • Sex Chromosomes:
– Male = X and Y
– Female = X and X
• “Normal” Numbers:
– 23 pairs OR 46 total
(2) Chromosomes:

6. • Chromosomes:
– Trisomy 21 = 3 chromosomes at #21
– Total = 47 chromosomes
• Physical Characteristics:
– Round-Asian-Like Facial features, short
stature, heart defects
– Shorter lifespan
– Prone to Alzheimer’s and leukemia
(3) Down Syndrome:

7. • Chromosomes:
– Trisomy 13 = 3 chromosomes at #13
– Total = 47 chromosomes
• Physical Characteristics:
– Eye, Brain and Circulatory defects
– Cleft Palate
– Death typical w/in months of birth
(4) Patau Syndrome:

8. • Chromosomes:
– Trisomy 18 = 3 chromosomes at #18
– Total = 47 chromosomes
• Physical Characteristics:
– Every organ defected
– Death w/in months after birth
(5) Edward’s Syndrome:

9. • Chromosomes:
– XXY
– Total = 47 chromosomes
• Physical Characteristics:
– Male sex organs, but underdeveloped + sterile
– Other feminine body characteristics
– Normal intelligence
(6) Klinefelter Syndrome:

10. • Chromosomes:
– Only 1 X chromosome
– Total = 45 chromosomes
• Physical Characteristics:
– Female
– Do not mature sexually + are sterile
– Short stature
– Normal Intelligence
– (Most die before birth)
(7) Turner’s Syndrome: