1. Human Genetics

2. Chromosomal Disorders
Nondisjunction – means “not coming apart”; when homologous chromosomes fail to separate, abnormal chromosome numbers may find their way into gametes
Monosomy – missing one chromosome from a pair
Trisomy – having three copies of a chromosome
Ex] Trisomy 21 – extra chromosome-21

3. A karyotype displays a diploid number of chromosomes.
Analyzing Karyotypes
A karyotype displays a diploid number of chromosomes.

4. How Are Karyotypes Made?

5. Human Female Karyotype
Human Karyotypes
Human Female Karyotype
Notation: 46, XX
Autosomes
Sex Chromosomes
Notation: 46, XY

6. Karyotype Analysis Is this person a male or a female?
What condition does this person have?
Trisomy 21 / Downs Syndrome
What was it caused by?
Nondisjunction 
What notation would you use to characterize this patient’s karyotype?
47, XY, +21

7. Recognizing Disorders in Karyotypes

8. 1.
Jacob’s Syndrome

9. 2.
Turner’s Syndrome

11. 3.
Cri-Du-Chat

13. 4.
Klinefeleter’s Syndrome

15. 5.
XXX Syndrome

16. Trisomy 13: Patau’s Syndrome6.
Trisomy 13: Patau’s Syndrome

17. WARNING:
You may not want to look at the next slide.

19. Trisomy 18: Edward’s Syndrome7.

21. 8.
Trisomy 21: Down’s Syndrome