Inv dup (8) (p21.1----22.1): further case report and a new hypothesis on the origin of the chromosome abnormality.

We report a male infant with a de novo inverted duplication of bands 8p 21.1----22.1. The clinical features up to 8 months of age and the enzyme investigations are described. A new cytogenetic hypothesis on the genesis of this rare chromosome aberration is also discussed.