The frequency of chromosome 7q interstitial deletions associated with B-cell lymphoproliferative disorders is substantially high among hematological malignancies.
OBJECTIVE
To study the frequency of interstitial 7q deletions in B-cell lymphoproliferative disorders (B-LPDs).


METHODS
Cases were collected from the clinical laboratory diagnosis database at USLabs/LabCorp over the past two years (2002 to 2004). Cases that showed deletions in the long arm of chromosome 7 were then reviewed. Interstitial deletions in the long arm of chromosome 7 were further investigated according to the indications for clinical laboratory studies and flow cytometry findings. The final clinical diagnosis for each case was obtained from the referring physician.


RESULTS
A total of 19,483 cases were included in this series. Eighty-five cases were observed to have either terminal or interstitial deletion in the long arm of chromosome 7. Of the 85 cases, 46 had interstitial deletions accounting for 54.1% of the 7q deletions combined. B-LPDs were found in 10 of the 46 cases, accounting for 21.7%. The B-LPDs associated with 7q interstitial deletions were diverse, including B-cell chronic lymphocytic leukemia (B-CLL) in five cases. The deleted region in the long arm of chromosome 7 in the 10 cases associated with B-LPDs was solely confined to the 7q22-q32 region.


CONCLUSIONS
(1) The frequency of 7q interstitial deletions associated with B-LPDs is substantially high; (2) 7q interstitial deletions are not uncommon in B-CLL.
Lu
Gary
G
Department of Pathology and Genetics, USLabs/LabCorp, Irvine, California 91612, USA. ghlu2003@yahoo.com
Zhang
John
J
Pauper
Katherine
K
D000368:Aged; D000369:Aged, 80 and over; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D002897:Chromosomes, Human, Pair 7; D005260:Female; D019337:Hematologic Neoplasms / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D007621:Karyotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000453:epidemiology* / Q000235:genetics*; D008297:Male; D008875:Middle Aged