ATI RN
Pediatric Genetic Disorders Questions
Question 1 of 5
The following are examples of autosomal dominant disorders EXCEPT
Correct Answer: D
Rationale: NF2 (A), Huntington (B), Marfan (C), are AD; Friedreich ataxia (D) is AR (GAA repeat on chromosome 9). Rationale: AD disorders need one allele; FRDA requires two.
Question 2 of 5
The MOST common genetic defect of Prader-Willi syndrome (PWS) is
Correct Answer: B
Rationale: PWS is most commonly due to paternal 15q11-13 deletion (B, ~70%). Rationale: Maternal deletion (A) causes Angelman; paternal UPD (C) is less common (~25%).
Question 3 of 5
A 24-year-old pregnant lady in 2nd trimester comes to your clinic worried about her exposure to CXR done for suspicion of pneumonia last week; she is highly concerned about possibility of congenital anomalies. Of the following, the BEST advice to her is that
Correct Answer: D
Rationale: A single chest X-ray (low dose, <0.1 mGy) is negligible. Rationale: Fetal risk is significant only >50 mGy; 2nd trimester is less sensitive than 1st.
Question 4 of 5
Children with Down syndrome are most likely diagnosed clinically in the neonatal period. All the following are characteristic facial features EXCEPT
Correct Answer: B
Rationale: Down syndrome features include macroglossia (A), hypoplastic midface (C), flat nasal bridge (D), and down-slanting fissures (E); flattened occiput (B) is not typical. Rationale: Occiput is often normal or prominent.
Question 5 of 5
You are evaluating a neonate with multiple dysmorphic features, you find him small for gestational age, microcephalic, single nostril, postaxial polydactyly and rocker-bottom feet. Of the following the MOST likely diagnosis is
Correct Answer: A
Rationale: Patau syndrome (trisomy 13, A) matches microcephaly, polydactyly, and rocker-bottom feet. Rationale: Single nostril (holoprosencephaly) is classic Patau.