ATI RN
Common Pediatric Genetic Disorders Questions
Question 1 of 5
Which of the following karyotypes is diagnostic of Down syndrome?
Correct Answer: A
Rationale: 46,XX,der(14;21)+21 indicates a translocation Down syndrome with an extra 21, totaling 47 chromosomes’ worth of material.
Question 2 of 5
Which of the following mutations is most likely to be lethal?
Correct Answer: D
Rationale: Frameshift mutations (e.g., 1-nucleotide insertion) disrupt the reading frame, often more lethal than substitutions or in-frame deletions.
Question 3 of 5
The karyotype where euchromatic regions stain more darkly and the light regions are heretochromatin is:
Correct Answer: D
Rationale: R-banding is correct. Rationale: Euchromatin is gene-rich and active, staining dark in R-banding with reverse Giemsa or fluorescent dyes, while heterochromatin (repetitive, inactive) stains light.
Question 4 of 5
What is the karyotype shown in the figure?
Correct Answer: C
Rationale: Without the figure, '46, XY' (C) is accepted. Rationale: 46, XY is a normal male karyotype, plausible for a typical question. 46, XX is female, 47, XY isn’t standard (e.g., could be XXY). 'C' aligns with a common male example.
Question 5 of 5
Chronic myeloid leukemia is caused by?
Correct Answer: A
Rationale: CML is caused by t(9;22) (Philadelphia chromosome, A). Rationale: BCR-ABL1 fusion drives uncontrolled myeloid proliferation. Trisomy 18 and 13 cause Edwards and Patau syndromes, not CML.