FISH analysis and multicolour banding pattern. A) Partial chromosome 3q paint (pcp 3q-green) of normal chromosomes 3 and of der(12), merged with 3q subtelomeric probe that hybridized at both ends of the additional segment (red). B) Hybridization of the subtelomeric probe 12p on the normal and the derivative chromosome 12. C) Multicolor banding analysis using specific probe sets for chromosomes 3 and 12. The resultant pattern proved that the additional material on der(12) resulted from an inverted duplication of the terminal portion of 3q.