ATI RN
Pediatrics Genetics Questions
Question 1 of 5
Of the following, the test /study that is required to be done periodically in persons with Down syndrome (DS) is
Correct Answer: D
Rationale: Thyroid function (D) is monitored in DS due to high hypothyroidism risk. Rationale: Congenital heart defects (C) are screened early, not periodically; thyroid issues emerge later.
Question 2 of 5
All are true about homeobox genes EXCEPT
Correct Answer: D
Rationale: Homeobox genes regulate development by determining tissue fate, acting as transcription factors, and controlling other genes. Mutations can cause aniridia (e.g., PAX6). However, tissues don’t typically revert to an undifferentiated state after homeobox gene action; their role is to direct differentiation, not reverse it.
Question 3 of 5
Down syndrome due to translocation of a third chromosome 21 is best described by all of the following EXCEPT
Correct Answer: C
Rationale: Translocation Down syndrome (4% of cases) involves chromosome 21 attaching to 13, 14, 15, or 21. Carriers are phenotypically normal, but recurrence risk is high (10-15% for mothers, lower for fathers). Phenotypes are not milder than trisomy 21.
Question 4 of 5
Karyotyping is not used in:
Correct Answer: C
Rationale: Karyotyping detects large chromosomal changes (deletions, inversions) but not small nucleotide insertions or point mutations, which require molecular techniques like sequencing.
Question 5 of 5
A chromosomal abnormality that involves 30 megabase region. The most likely abnormality to cause the worse disease is:
Correct Answer: A
Rationale: Deletion of a 30 Mb region removes many genes, likely causing severe disease (e.g., developmental delay). Duplications or inversions (pericentric/paracentric) may disrupt gene dosage or structure but are typically less severe than outright loss.