"The 3p deletion syndrome, like most chromosomal deletion syndromes, is highly variable in its clinical presentation. However, based on past experience (which may or may not withstand the test of time, as more children are identified with this diagnosis), there are a few generalizations that can be made.
First, most children with 3p deletion have developmental delay, and most have relatively small body size as they grow. In addition, there are some distinctive facial features shared by many children with 3p deletion, including ptosis (drooping eyelids), a broad bridge of the nose, distinctive looking ears, and low muscle tone. Some have widely spaced eyes, and eyebrows that connect in the middle, and some have an extra digit.
However, it is very important for parents to realize that their child is unique, and may have a unique outlook. Rarely, the child's outlook is not as positive as other children, but it is far more likely, on average, that a child identified today with a chromosomal deletion syndrome, will have a more optimistic outlook. That is because genetic specialist physicians are ordering new chromosome deletion tests (such as the chromosomal microarray) on a much broader population of children.
Despite the understandable interest in new diagnostic technologies in genetics, it is very important for parents to keep in mind that they only provide a molecular explanation for what is already known about a child.
Infrequently, additional worries are introduced by a chromosomal diagnosis, but doctors are typically quick to explain this to parents. The most likely situation, however, is that the child's recent developmental progress and state of health is by far the best predictor of how the child will continue to do in the near future. Predicting the long-term future is impossible for any child, with or without a chromosomal diagnosis. All parents can thus reasonably hope for the best, given the details of the child's current health and developmental status, while being prepared for any challenges that may occur in the long-term, and taking on the joys (and the occasional angst) of parenting one day at a time." Thomas Morgan, MD Dept. of Genetics and Yale Child Study Center Yale University