A third case of de novo partial trisomy 4p.

Interestingly, the previously reported patient with a different but overlapping deletion of chromosome 12 long arm (q13.3-q21.1) and the subject of this report have only a few features in common (table). The deletion in each includes the portion 12q13.3 to q21. 1. It is unclear whether the small difference in the portion of 12q deleted accounts for the fact that they do not resemble each other to a greater extent. The delineation of a syndrome associated with interstitial deletion of 12q must await reports of additional cases. The detection of subtle chromosome abnormalities such as this show the need for minimum standards for routine studies of those at risk for chromosome abnormalities. Our impression is that these minimum standards should include well banded chromosomes of the 450 to 550 band stage.