Partial 2p trisomy was diagnosed (by the G-banding method) in two sibs with multiple congenital defects. Their father showed a balanced translocation 46,XY,rcp(2;15)(p21;q26) (so the patients were the result of a paternal adjacent-1 meiotic segregation). The clinical features of the two affected cases are compared with other cases previously reported of partial 2p trisomy in order to individualize the syndrome.