Having duplications or deletions of an entire group of genes spells trouble for living organisms. Potocki-Lupski syndrome, for instance, is a condition that results from having an extra copy of a small piece of chromosome 17 – 17p11.2 – in each cell. A different condition, known as Smith-Magenis syndrome, results when a similar small piece of chromosome 17 is deleted. It was thought that these conditions occurred because of the imbalance in the genetic information contained in the altered piece of chromosome 17, but researchers in the lab of Dr. James R. Lupski and their colleagues have discovered that much more is going on than deletions or duplications. Xiaofei Song, a graduate student in Dr. Lupski's lab, was a co-author on this paper.