Mosaicism for duplication 12q (12q13-->12q21.2) accompanied by a pericentric inversion in a dysmorphic female infant.

While several case reports describe partial trisomy 12qter, reports of interstitial 12q duplications are extremely rare. We present here the clinical findings in a female infant with mosaicism for a duplication of chromosome 12q13.3→12q21.2 accompanied by a pericentric inversion (12)(p13.3q21.2). No other cases with an interstitial duplication for this region have been reported. The female infant has several dysmorphic anomalies but has no symptoms associated with the clinically distinguishable syndrome of 12q duplication. Since the duplication is maternally isodisomic, the rearrangement is most likely of postzygotic origin.