Familial Chromosomal Segregation. A) Partial karyotype of each family member showing chromosomes 10, 15 and the translocation; Proband (III-1): 45,XX,der(10)t(10;15)(q26.3;q11.2),-15; mother (II-2): 46,XX,t(10;15)(q26.3;q11.2); grandfather (I-1): 46,XY,t(10;15)(q26.3;q11.2); maternal uncle (II-3): 47,XY,+der(15)t(10;15)(q26.3;q11.2) and his daughter (III-2): 47,XX,+der(15)t(10;15)(q26.3;q11.2). Red rectangle shows the 15q11 microdeletion in the grandfather and maternal uncle. B) Schematic representation of array CGH results of 15q11.1q11.2 and 10q26.3 chromosomal regions in the five available family members. The deletions (x1, green), and duplications (x3, red) are shown as rectangular boxes on the left or the right of the vertical chromosomic lines, respectively. The chromosomal imbalance between the maternal uncle (II-3) and his daughter (III-2) can be explained, because he had the same deletion in the non-translocated chromosome 15, as his father (I-1).