The baby's hand has a transverse crease as well as a single flexion crease on the fifth digit. These features are most suggestive of Down syndrome (trisomy 21). Only about 20% of cases of Down syndrome will have the single flexion crease on the fifth digit, but it is a helpful finding for diagnosis, since the morphologic features of Down syndrome can be quite subtle. Though the risk for Down syndrome increases with maternal age, most cases of trisomy 21 will be seen in younger mothers, simply because there are far more pregnancies in 20 year olds than in 40 year olds.
| Our winner is: Mark Tsai of Pittsburgh, Pennsylvania, USA
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