We describe a liveborn male with a de novo deletion of 4(q21q25). The findings in this infant are compared with those of other 4q interstitial deletion patients with similar break-points. Given the reproducible findings including skull asymmetry, cardiac defects, renal cysts, "butterfly" vertebrae, as well as a particular dysmorphic face with developmental delay, there is evidence for an interstitial 4q deletion syndrome.