[Duplication of the long arm of chromosome 3 (dup 3q) in a newborn infant whose the father is carrier of pericentric inversion of chromosome 9].

The authors report a case of a partial trisomy for the long arm of chromosome 3. The associated morphotypic anomalies are compared with the 31 cases already reported, and allow to further outline a well recognizable morphotype which has similarities with the Brachmann Cornelia de Lange Syndrome. The chromosomal mechanisms which may result in this unbalanced caryotype dup 3 q are discussed, and among them the possible role of a paternal chromosome 9 pericentric inversion, most commonly termed as a normal variant.