ATI RN
Common Pediatric Genetic Disorders Questions
Question 1 of 5
The percentage of DNA sequence variation between humans is the lowest in:
Correct Answer: D
Rationale: Exons (coding regions) have the lowest variation between humans (~0.1%) due to evolutionary conservation of protein function. Non-coding regions (repeats, introns, transposable elements) tolerate more variation.
Question 2 of 5
In a patient with nonhereditary caner. The driver mutations:
Correct Answer: B
Rationale: Nonhereditary cancer driver mutations are somatic, present in primary and metastatic tumors but not normal tissue.
Question 3 of 5
A child with cleft palate, a heart defect, and extra fifth fingers is found to have 46 chromosomes with extra material on one homologue of the chromosome 5 pair. This chromosomal abnormality is best described by which of the following terms?
Correct Answer: D
Rationale: Extra material on one chromosome 5 with a total of 46 chromosomes indicates an unbalanced rearrangement (e.g., partial duplication), causing phenotypic abnormalities.
Question 4 of 5
The most common lethal genetic disease in the United States is:
Correct Answer: B
Rationale: Cystic fibrosis is the most common lethal autosomal recessive disorder in the U.S., with significant morbidity and mortality.
Question 5 of 5
The genetic disease cystic fibrosis is caused by a defective allele that:
Correct Answer: C
Rationale: Cystic fibrosis is caused by mutations in the CFTR gene, leading to a defective chloride channel protein, affecting mucus and sweat production.