Molecular Biology/Genetics USMLE Step 1 Practice Question
A 2-year-old girl presents with global developmental delay, intellectual disability, and multiple congenital anomalies including cardiac defects. Vital signs are stable (BP 95/60, HR 110, RR 24, Temp 37°C). Standard karyotype and targeted FISH studies are normal. Laboratory studies show no metabolic abnormalities. Her geneticist seeks an unbiased, genome-wide method to detect submicroscopic deletions and duplications across all chromosomes without prior knowledge of specific loci. Which test is most appropriate?
Answer choices
- ARestriction fragment length polymorphism analysis only
- BWestern blot
- CSanger sequencing of mitochondrial DNA only
- DSerum protein electrophoresis
- EComparative genomic hybridization microarrayCorrect answer
- FStandard karyotype
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