1. Chromosomal Disorders

2. Amniocentesis

3. Single Chromosome Disorders 1.Deletion Genetic material is missing 2. Duplication Genetic material is present twice 3. Inversion Genetic material is “flipped”

4. Translocation (involves 2 chromosomes) Translocation Genetic material is added or swapped from another chromosome

5. Chromosomal Non-disjunction when cells go through meiosis, the chromosomes don’t separate correctly and either too many or not enough are passed on.

6. What is Trisomy? Any extra chromosome Happens during non-disjunction! The non-disjunction rate increases with Mom’s age Incidence: –1/750 live births. –Mothers in their early twenties have a risk of 1/1,500. –Women over 35 have a risk factor of 1/70, which jumps to 1/25 for women 45 and over.

7. An Example of Trisomy Down’s Syndrome – A.k.a- trisomy 21 – Shorthand: 47, XY or XX, +21 – Survival rate is very high for this non- disjunction!

8. Short stature, broad hands, stubby fingers and toes, a wide rounded face, a large protruding tongue that makes speech difficult. Individuals with this syndrome have a high incidence of respiratory infections, heart defects, and leukemia.

9. Edward’s Syndrome This karyotype demonstrates trisomy 18 Shorthand: (47, XY, +18). - Incidence is only 1 in 8000 live births. - It is uncommon for fetuses with this condition to survive

10. Patau’s Trisomy Syndrome 1 in 14,000 births 47 chromosomes XY or XX #13 Trisomy Nondisjunction Small head Small or missing eyes Heart defects Extra fingers Abnormal genitalia Mentally retarded Cleft palate Most die a few weeks after birth

11. Klinefelter Syndrome 1 in 1,100 births 47 chromosomes XXY only #23 Trisomy Nondisjunction Scarce beard Male anatomy Sterile Delicate skin Low mental ability Normal lifespan

12. Monosomy Monosomy- having one fewer chromosome in each body cell. Generally, if a chromosomal mutations occurs during meiosis, one half of the gametes will have monosomy and the other half will have trisomy

13. Turners Syndrome 1 in 5,000 births 45 chromosomes X only #23 Monosomy Nondisjunction 96-98% do not survive to birth No menstruation No breast development Narrow hips Broad shoulders and neck

14. Cri-Du-Chat Syndrome 1 in 216,000 births 46 chromosomes #5 Deletion of lower arm Symptoms: Moon-shaped face Heart disease Mentally retarded Malformed larynx Normal lifespan