ATI RN
Pediatric Genetics Questions
Question 1 of 5
A fullterm baby with multiple congenital anomalies, his blood film reported nuclear projections in neutrophils. Of the following the MOST likely diagnosis is
Correct Answer: A
Rationale: Nuclear projections (e.g., drumsticks) in DS neutrophils (A) are a feature. Rationale: Other syndromes (B-E) lack this specific hematologic sign.
Question 2 of 5
Trinucleotide repeats are implicated in the etiology of all of the following EXCEPT
Correct Answer: B
Rationale: Trinucleotide repeats cause fragile X (CGG), Friedreich ataxia (GAA), spinocerebellar ataxia type I (CAG), and myotonic dystrophy (CTG). Neurofibromatosis is caused by mutations in NF1 or NF2 genes, not trinucleotide repeats.
Question 3 of 5
Prader-Willi syndrome may occur from a uniparental maternal disomy of chromosome 15. There is no parental chromosome 15. The expressed phenotype is an example of
Correct Answer: C
Rationale: Prader-Willi results from loss of paternal 15q11-13 (via deletion or maternal uniparental disomy). This is imprinting, where gene expression depends on parental origin. Penetrance, expressivity, mitochondrial inheritance, and nondisjunction don’t apply.
Question 4 of 5
The nomenclature c.2312_2314delinGCGTGGACAAC G denotes:
Correct Answer: D
Rationale: c.2312_2314del indicates deletion of 3 nucleotides (positions 2312-2314). ‘insGCGTGGACAACG’ indicates insertion of 12 nucleotides (GCGTGGACAACG). Thus, it’s a 3-nucleotide deletion followed by a 12-nucleotide insertion.
Question 5 of 5
A couple are both tested, the father is affected with cystic fibrosis and the mother is a carrier of cystic fibrosis gene. What is the chance that they will have a HOMOZYGOUS NORMAL MALE?
Correct Answer: C
Rationale: Father (affected, ff) contributes f. Mother (carrier, Ff) contributes F or f (1/2 each). Child genotypes: Ff (carrier) or ff (affected). No FF (homozygous normal) is possible, so chance = 0. Sex (male) doesn’t change this.