A 1-day-old newborn girl is evaluated for failure to thrive and weak cry. She was born at 36 weeks via spontaneous vaginal delivery to a 34-year-old mother. The pregnancy was complicated by intrauterine growth restriction noted on ultrasound and polyhydramnios. On physical examination, the infant has micrognathia, clenched hands with overlapping fingers, a prominent occiput, and rocker-bottom feet. A cardiac murmur is present. Prenatal genetic testing was declined. Which of the following is the most likely karyotype abnormality in this infant?
