A I-hour-old girl born to a 40-year-old woman is brought to the nursery for evaluation. The pregnancy and delivery were uncomplicated Physical examination shows mid-face hypoplasia with a flat nasal bridge, up-slanting palpebral fissures, a small mouth, and a single palmar crease bilaterally. Cardiac auscultation reveals a blowing holosystolic murmur heard best along the sternal border. Which of the following mechanisms is the most likely cause of this infants clinical findings? A. C) A. Genomic imprinting B. C) B. Mosaicism C. C) C. Partial deletion D. (D D. Triplet expansion E. C) E. Uniparental disomy