Inverted tandem duplication generates a duplication deficiency of chromosome 8p

Abstract

An adult female with severe mental retardation and dysmorphic features is described. A de novo chromosomal aberration involving 8p was found. The karyotype was 46, XX, inv dup (8) (p12—-p23.1). Dosage studies with the DNA probe D8S7, which is located at 8p23—-8pter, showed that the patient was monosomic for this marker. Thus the de novo rearrangement generated a duplication-deficiency chromosome. The possible mechanisms of formation of this abnormal chromosome are discussed.