Dup(12)(q13-q22) and 13q14 deletion in a case of B-cell chronic lymphocytic leukemia.
Cases with partial trisomy 12 have rarely been found in B-cell chronic lymphocytic leukemia (CLL). We report our clinical, cytogenetic and fluorescence in situ hybridization (FISH) findings in a CLL patient with a duplication of part of the long arm of chromosome 12 between bands q13-q22. This patient was the only case with this duplication among the 112 cases (0.9%) of CLL cytogenetically analyzed in our laboratory. FISH studies using unique-sequence specific probes for the RB-1 (retinoblastoma) gene and the D13S319 locus at the 13q14 band showed a monoallelic loss for the D13S319 locus (20% of cells) with a diploid RB-1 gene. Our case showed an atypical morphology (35% prolymphocytes), a high proliferation rate and progression of the disease, indicating that the duplication of this region may be equivalent to complete trisomy 12 in CLL patients.
Chena
C
C
Departamento de Genética, Instituto de Investigaciones Hematológicas Mariano R. Castex, Academia Nacional de Medicina, Pacheco de Melo 3081, 1425-Buenos Aires, Argentina.
Sarmiento
M
M
Palacios
M F
MF
Scolnik
M
M
Slavutsky
I
I
D000368:Aged; D000483:Alleles; D002455:Cell Division / Q000235:genetics; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D020732:Cytogenetic Analysis; D018450:Disease Progression; D005260:Female; D017353:Gene Deletion; D020440:Gene Duplication; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D012175:Retinoblastoma / Q000235:genetics; D014314:Trisomy