ATI RN
Pediatrics Genetics Questions
Question 1 of 5
Which of the following conditions is caused by a trinucleotide (triplet) repeat expansion?
Correct Answer: C
Rationale: Huntington disease is caused by CAG repeat expansion in the HTT gene.
Question 2 of 5
Which of the following conditions shows anticipation in paternal transmission?
Correct Answer: D
Rationale: Fragile X syndrome shows anticipation (worsening with generations) via triplet repeat expansion, often more pronounced in paternal transmission.
Question 3 of 5
Which of the following causes female pseudohermaphroditism?
Correct Answer: C
Rationale: Congenital adrenal hyperplasia (e.g., 21-hydroxylase deficiency) causes excess androgens, masculinizing XX females.
Question 4 of 5
A 31-year-old man has a unilateral breast lump. A biopsy is performed, and the pathology report, surprisingly, shows an early-stage carcinoma. The man’s family history reveals no history of breast cancer. What would the physician be most likely to advise?
Correct Answer: B
Rationale: Male breast cancer suggests possible Klinefelter syndrome (47,XXY), warranting a karyotype to assess sex chromosomes.
Question 5 of 5
The figure below is the pedigree demonstrating the recurrence of Osteogenesis imperfecta in children with their father unaffected (arrow)
Correct Answer: A
Rationale: OI is AD. Unaffected father with affected kids suggests germline mosaicism; figure unavailable.