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Characterisation of dic(9;20)(p11–13;q11) in childhood B‐cell precursor acute lymphoblastic leukaemia by tiling resolution array‐based comparative genomic hybridisation reveals clustered breakpoints at 9p13.2 and 20q11.2
Author(s) -
Schoumans Jacqueline,
Johansson Bertil,
Corcoran Martin,
Kuchinskaya Ekaterina,
Golovleva Irina,
Grandér Dan,
Forestier Erik,
Staaf Johan,
Borg Åke,
Gustafsson Britt,
Blennow Elisabeth,
Nordgren Ann
Publication year - 2006
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.2006.06328.x
Subject(s) - breakpoint , comparative genomic hybridization , biology , microbiology and biotechnology , gene , genetics , gene duplication , gene rearrangement , chromosomal translocation , genome
Summary Although the dic(9;20)(p11–13;q11) is a recurrent chromosomal abnormality in paediatric B‐cell precursor acute lymphoblastic leukaemia (BCP ALL), occurring in approximately 2% of the cases, its molecular genetic consequences have not been elucidated. In the present study, high‐resolution genome‐wide array‐based comparative genomic hybridisation (array‐CGH) and fluorescence in situ hybridisation (FISH) were used to characterise the 9p and 20q breakpoints (BPs) in seven childhood BCP ALLs with dic(9;20), which was shown to be unbalanced in all of them, resulting in loss of 9p13.2‐pter. Five of the cases had loss of 20q11.2‐qter, whereas two displayed gain of 20cen‐pter. All BPs on 9p clustered in a 1.5 Mb segment of the sub‐band 9p13.2; in three of the cases, the 20q BPs mapped to three adjacent clones covering a distance of 350 kb at 20q11.2. Thus, the aberration should be designated dic(9;20)(p13.2;q11.2). One of the ALLs, shown to have a complex dic(9;20), was further investigated by FISH, revealing a rearrangement of the haemapoietic cell kinase isoform p61 ( HCK ) gene at 20q11. The disruption of HCK may result in a fusion gene or in loss of function. Unfortunately, lack of material precluded further analyses of HCK . Thus, it remains to be elucidated whether dic(9;20)(p13.2;q11.2) leads to a chimaeric gene or whether the functionally important outcome is loss of 9p and 20q material.