1. Karyotypes
Objective: 6H - describe how techniques such as DNA fingerprinting, genetic modifications, and chromosomal analysis are used to study the genomes of organisms

2. Human Female Karyotype
Karyotypes
Human Female Karyotype
Autosomes
Sex Chromosomes
Autosomes
Sex Chromosomes
Notation:
46,XY
Notation:
46,XX
Diagnosis: Normal male
Diagnosis: Normal female

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

4. Chromosomal disorders
Nondisjunction – means “not coming apart”;
- when homologous chromosomes fail to separate, abnormal chromosome numbers may find their way into gametes

5. Exp. Trisomy 18 – extra chromosome 18
Monosomy – missing one chromosome from a pair
Exp. Monosomy 23 – missing a sex chromosome
Notation: 45,X0
Trisomy – having three copies of a chromosome
Exp. Trisomy 18 – extra chromosome 18
Notation: 47,XX,+18 or 47,XY,+18

6. No Nondisjunction male 47, XY, +21 Trisomy 21
Does this person have a normal # of chromosomes?
What was it caused by?
Is this person a male or a female?
What notation would you use to characterize this patient’s karyotype?
What condition does this person have?    No
Nondisjunction
male
47, XY, +21
Trisomy 21
(Down Syndrome)

7. Common Non-disjunction Disorders
Turner’s Syndrome – Monosomy 23 Notation: 45,X0
Kleinfelter’s Syndrome – Trisomy 23 Notation: 47,XXY
Down’s Syndrome – Trisomy 21
Notation: 47,XX,+21 or 47,XY,+21
Edward’s Syndrome – Trisomy 18
Notation: 47,XX,+18 or 47,XY,+18
Patau Syndrome – Trisomy 13
Notation: 47,XX,+13 or 47,XY,+13

8. Amniocentesis a procedure a pregnant woman
can have in order to detect some
genetics disorders…such as
non-disjunction.
Amniotic fluid withdrawn

9. How are Karyotypes made?
Add chemical to stimulate mitosis
Add chemical to stop mitosis in metaphase
Eventually, stain chromosomes
Identify & photograph chromosomes
Cut out chromosomes & arrange into karyotype

10. Practice:
What is the sex of this patient?
What notation would you give this patient?
What diagnosis would you give this patient?
Female (Why? No Y chromosome)
45, XO
Monosomy 23

11. Now, you are going to pretend to be a geneticist and diagnose patients by looking at karyotypes.
Karyotype Activity
Due Today