Interstitial deletion of chromosome 22 in a patient with the DiGeorge malformation sequence.

We describe a chromosome 22 deletion in a patient with the DiGeorge malformation sequence as manifested by an interrupted aortic arch, mild thymic hypoplasia, and minor craniofacial anomalies. Although others have reported DiGeorge sequence patients with deletions derived from unbalanced translocations involving the chromosome 22 long arm, the small interstitial deletion described here appears to be unusual for patients with this disorder.