ATI RN
Pediatric Genetic Disorders Questions
Question 1 of 5
Multifactorial inheritance is characterized by all of the following EXCEPT
Correct Answer: C
Rationale: Multifactorial inheritance involves multiple genes and environment, with sex predilection (e.g., pyloric stenosis), recurrence rates of 2-10%, and twin concordance of 20-63%. Severe symptoms can increase risk. Symptomatic carriers apply to monogenic traits, not multifactorial.
Question 2 of 5
The most common occurring mutations in humans are:
Correct Answer: D
Rationale: Aneuploidy (e.g., trisomy 21) is the most common chromosomal mutation in humans, especially in live births or conceptions. Indels and CNVs are frequent but less so, and polyploidy is rare in humans.
Question 3 of 5
This is an electrophoresis (southern blots) for an individual with hereditary retinoblastoma; both normal and tumor cells were genotyped for three polymorphic markers flanking the RBI locus on chromosome 13 for this patient (N=normal cells, T=tumor cells). Based on the figure, which of the following is the most likely to explain the genetic mutation in this patient's cancer?
Correct Answer: A
Rationale: Hereditary retinoblastoma involves one germline RB1 mutation. Tumorigenesis requires a second hit (Knudson’s two-hit hypothesis). Southern blot showing loss of normal allele in tumor cells suggests a second somatic mutation, not chromosome loss.
Question 4 of 5
Which of the following is NOT a familial cancer syndrome:
Correct Answer: C
Rationale: Waardenburg syndrome causes pigmentation/hearing issues, not cancer. Others (Li-Fraumeni, NF2, FAP) are cancer syndromes.
Question 5 of 5
Next Generation Sequencing (NGS) can perform Whole Exome Sequencing (WES) for the entire coding regions in one reaction. WES will be more successful in detecting a candidate disease-causing change in:
Correct Answer: D
Rationale: WES targets exons (coding regions) and is best at detecting synonymous splicing variants (affecting splice sites within exons). Promoters, enhancers, and imprinting are outside exonic focus.