Dysmorphology
Down's Syndrome
Down's syndrome is clearly the most common and recognizable genetic syndrome known, although at times the physical features may be difficult to identify in a newborn. This hispanic infant has fairly typical facial features of Down's syndrome: upslanting palpebral fissures, a suggestion of epicanthal folds, and a flat nasal bridge.
photo by Janelle Aby, MD
Down's Syndrome
The other striking physical finding in this newborn was hypotonia. When this infant was lifted off the bed, the examiner had to give much more than the typical amount of support to the infants' head and shoulders, and still the arms flop back towards the bed. The sensation is similar to handling a rag doll. For a newborn, hypotonia of this degree can significantly impact the baby's ability to feed well, so breastfeeding should be carefully monitored.
photo by Janelle Aby, MD
Down's Syndrome
In contrast, this pretem newborn does not exhibit typical facial features of Down's syndrome. In this case, the diagnosis was made after duodenal atresia was detected. Because trisomy 21 affects all the cells in the body, clinical symptoms related to the underlying diagnosis can appear in practically every organ system. Evaluation is generally guided by symptoms, but it is reasonable to screen every baby with Down's syndrome with cardiac echo (as heart defects are noted in 50%), and with a complete blood count (as congenital leukemia can occur).
photo by Henry Lee, MD
