Mosaicism for terminal deletion of 4q.

Chromosomal imbalance affecting the long arm of chromosome 4 has been reported in a variety of distinct clinical conditions. Common clinical findings have been described for 4q deletions distal to 4q33 and termed as 4q terminal deletion syndrome. We report two children with de novo chromosomal abnormality consisting of a terminal deletion (q33qter) of chromosome 4 in mosaic form. The phenotypes of these two patients are very similar to that described in the literature, but milder because of the mosaic nature of cytogenetic abnormality.