Fig. 2

Cytogenetic, FISH and array-CGH studies. a Proband’s QFQ-banded chromosomes 14 and 21; the arrow shows the derivative 21. b FISH with subtelomeric 14q probe of the proband: the der(21) is arrowed. c Father’s QFQ-banded partial metaphase with two derivative chromosomes arrowed. d Father’s GTG-banded partial metaphase with two derivative chromosomes arrowed. e FISH with subtelomeric 14q probe of the father: hybridization signals are present on the normal 14 and on der(21). f Chromosome 14 view showing the duplication in array-CGH (left) and a schematic representation of supposed NAHR mechanism for translocation formation (right)