Write the karyotype for the following situations:
1. Normal female with a balanced Robertsonian translocation
between chromosomes 13 and 21
2. Normal male with a balanced translocation between
chromosome 10 and chromosome 7 with breakpoints on the long arm
of 10 at band 22 and on the short arm of 7 at band 12
3. Down syndrome boy
4. Turner syndrome girl
5. Normal female with an inverted segment of chromosome
10 with breakpoints on the short arm at band 12 and on the long
arm at band 22
Use a T or F to indicate whether each
statement is true or false.
6. The incidence of Down syndrome rises with increasing
maternal age.
7. Blood should be received in the genetics laboratory
within 24 to 48 hours of sampling.
Indicate what type of sample should be sent for a
chromosome study in the following situations:
8. To diagnose chromosome abnormality in the patient
9. To rule out mosaicism
10. To rule out a chromosome abnormality as the cause
of a miscarriage
11. To rule out a fetal chromosome abnormality in
pregnant older mothers
12. To diagnose leukemia/cancer
LESSON 1 POSTTEST: ANSWERS
1. 45,XX,t(13;21)
2. 46,XY,t(7;10)(p12;q22)
3. 47,XY,+21
4. 45,X
5. 46,XX,inv(10)(p12;q22)
6. True
7. True
8. Blood
9. Skin
10. Product of conception
11. Amniotic fluid
12. Bone marrow
Table of Contents- Lesson 1