MID - Autosomal Aneuploidy (Quiz)

Exam Title: Autosomal Aneuploidy Examination

Instructions: Read each question carefully and choose the best answer.

I. Identification (10 items):

1. The term referring to an abnormal number of non-sex chromosomes. Answer: Autosomal Aneuploidy

2. The process where chromosomes fail to separate properly during cell division. Answer: Nondisjunction

3. The condition where some cells in an individual have a normal chromosome count and others do not. Answer: Mosaicism

4. The most common autosomal aneuploidy, characterized by an extra copy of chromosome 21. Answer: Trisomy 21 (Down Syndrome)

5. A severe autosomal aneuploidy involving an extra copy of chromosome 18. Answer: Trisomy 18 (Edwards Syndrome)

6. An autosomal aneuploidy associated with an extra copy of chromosome 13. Answer: Trisomy 13 (Patau Syndrome)

7. The loss of one copy of a chromosome. Answer: Monosomy

8. A prenatal diagnostic test that involves sampling the fluid surrounding the fetus. Answer: Amniocentesis

9. A prenatal diagnostic test that involves taking a sample of placental tissue. Answer: Chorionic Villus Sampling (CVS)

10. A visual representation of an individual's chromosomes, used to detect abnormalities. Answer: Karyotyping

II. Multiple Choice (10 items):

11. Autosomal aneuploidy is primarily caused by:

    a) Mutations in single genes

    b) Errors in chromosome separation during cell division

    c) Environmental factors

    d) Sex-linked inheritance

    Answer: b) Errors in chromosome separation during cell division

12. Which of the following is NOT a common type of autosomal aneuploidy mentioned in the text?

    a) Trisomy 21

    b) Trisomy 18

    c) Trisomy 13

    d) Trisomy 23

    Answer: d) Trisomy 23

13. Individuals with Trisomy 21 typically have:

    a) Severe intellectual disability and rocker-bottom feet

    b) Mild to moderate intellectual disability and distinct facial features

    c) Cleft lip/palate and polydactyly

    d) Skeletal abnormalities and deep furrows on the soles of feet

    Answer: b) Mild to moderate intellectual disability and distinct facial features

14. Edwards Syndrome (Trisomy 18) is often associated with:

    a) Increased risk of leukemia

    b) Survival beyond the first year in most cases

    c) Clenched fists with overlapping fingers and rocker-bottom feet

    d) Mild intellectual disability

    Answer: c) Clenched fists with overlapping fingers and rocker-bottom feet

15. Holoprosencephaly, a condition where the brain hemispheres fail to separate properly, is a characteristic of:

    a) Trisomy 21

    b) Trisomy 18

    c) Trisomy 13

    d) Trisomy 8

    Answer: c) Trisomy 13

16. Trisomy 8 (Warkany Syndrome 2) typically occurs in:

    a) Full form, leading to live births with severe disabilities

    b) Mosaic form, where some cells have the extra chromosome

    c) All cells, with a high survival rate

    d) Only in males

    Answer: b) Mosaic form, where some cells have the extra chromosome

17. Monosomy 21 is described in the text as:

    a) A common condition with mild effects

    b) Extremely rare and usually lethal before birth

    c) More common in females than males

    d) Treatable with gene therapy

    Answer: b) Extremely rare and usually lethal before birth

18. Which prenatal testing method is non-invasive?

    a) Amniocentesis

    b) Chorionic Villus Sampling (CVS)

    c) Karyotyping

    d) Non-invasive prenatal testing (NIPT)

    Answer: d) Non-invasive prenatal testing (NIPT)

19. Karyotyping is a diagnostic tool used to:

    a) Detect single gene mutations

    b) Identify chromosomal abnormalities

    c) Measure hormone levels

    d) Assess metabolic function

    Answer: b) Identify chromosomal abnormalities

20. The primary focus of management and treatment for autosomal aneuploidy is:

    a) Curing the condition with medication

    b) Replacing the missing or extra chromosome

    c) Managing symptoms and improving quality of life

    d) Preventing the condition in future pregnancies

    Answer: c) Managing symptoms and improving quality of life

III. Fill in the Blanks (10 items):

21. Autosomal aneuploidy involves an abnormal number of ____________________ chromosomes. Answer: autosomes (non-sex)

22. The failure of chromosomes to separate properly during meiosis is called ____________________. Answer: nondisjunction

23. Trisomy 21 is also known as ____________________ Syndrome. Answer: Down

24. An extra copy of chromosome ____________________ results in Edwards Syndrome. Answer: 18

25. Rocker-bottom feet are a characteristic symptom of ____________________ Syndrome. Answer: Edwards

26. Trisomy 13 is also known as ____________________ Syndrome. Answer: Patau

27. ____________________ is the failure of the brain hemispheres to separate properly, seen in Trisomy 13. Answer: Holoprosencephaly

28. An extra copy of chromosome 8, typically in mosaic form, leads to ____________________ Syndrome 2. Answer: Warkany

29. The loss of one copy of chromosome 21 is called Monosomy 21 and is usually ____________________. Answer: lethal

30. ____________________ counseling is important for parents with a family history of aneuploidy. Answer: Genetic

IV. True or False (10 items):

31. Autosomal aneuploidy affects the sex chromosomes. Answer: False

32. Nondisjunction can occur during meiosis I or meiosis II. Answer: True

33. Trisomy 21 is the least common autosomal aneuploidy. Answer: False

34. Advanced maternal age is a known risk factor for Trisomy 21, 18, and 13. Answer: True

35. There is a cure for Edwards Syndrome. Answer: False

36. Polydactyly (extra fingers or toes) is a common feature of Trisomy 18. Answer: False (It's a feature of Trisomy 13)

37. Full Trisomy 8 is usually survivable to adulthood. Answer: False

38. Non-invasive prenatal testing (NIPT) is a definitive diagnostic test for aneuploidy. Answer: False (NIPT screens for risk; invasive tests confirm diagnosis)

39. Karyotyping can detect partial aneuploidy like deletions or duplications. Answer: True

40. Management of autosomal aneuploidy aims to correct the chromosomal abnormality. Answer: False

V. Punnett Square Problems (Adaptation for Aneuploidy) (10 items):

41. A woman of advanced maternal age (40 years old) is pregnant. Based on the information in the text, is she at an increased risk of having a child with Trisomy 21 compared to a younger woman?

    Answer: True (Advanced maternal age is a risk factor)

42. A couple has a child with Trisomy 18 due to nondisjunction. What is the probability that their next child will also have Trisomy 18 due to the same cause? (Note: This is a complex question and the simple answer based on the text is that the risk is generally low but slightly increased compared to the general population. Answer True or False based on increased risk.)

    Answer: True (There is a slightly increased recurrence risk)

43. A couple undergoes amniocentesis, and the karyotype of the fetus shows 47 chromosomes with an extra chromosome 13. What condition does the fetus have?

    Answer: Trisomy 13 (Patau Syndrome)

44. A family has a history of chromosomal translocations involving chromosome 13. According to the text, are they at an increased risk of having a child with Trisomy 13?

    Answer: True (Parents carrying balanced translocations involving chromosome 13 are at increased risk)

45. A prenatal screening test (NIPT) indicates a high risk for Trisomy 21. Does this definitively mean the baby will have Down Syndrome?

    Answer: False (NIPT is a screening test and requires confirmation with diagnostic tests like amniocentesis or CVS)

46. A child is born with a flat facial profile, upward-slanting eyes, and a single palmar crease. Which autosomal aneuploidy is most likely?

    Answer: Trisomy 21 (Down Syndrome)

47. An infant presents with severe intellectual disability, microcephaly, and clenched fists with overlapping fingers. Which autosomal aneuploidy is most likely?

    Answer: Trisomy 18 (Edwards Syndrome)

48. An infant is born with a cleft lip and palate, microphthalmia, and polydactyly. Which autosomal aneuploidy is most likely?

    Answer: Trisomy 13 (Patau Syndrome)

49. If a karyotype shows 47 chromosomes with an extra chromosome 8 in some cells, what condition is indicated?

    Answer: Mosaic Trisomy 8 (Warkany Syndrome 2)

50. A couple has had one child with Trisomy 21. They are considering having another child. Should they seek genetic counseling?

    Answer: True (Genetic counseling is important for understanding recurrence risks)