Zbornik - Društvo genetičara Srbije

210 ZBORNIK ABSTRAKATA III KONGRESA GENETIÈARA SRBIJE V-Pos-7
Subotica, 30. novembar - 4. decembar 2004.
TRANSLOKACIJA t(8;21)(q22;q22) I NJENE VARIJANTE U AKUTNOJ
MIJELOIDNOJ LEUKEMIJI
Jelica Jovanoviæ, Vesna Ðorðeviæ, Marija Denèiæ-Fekete, Sandra Biiæ,
Mirjana Gotiæ i Darinka Boškoviæ
Institut za hematologiju, Klinièki centar Srbije, Beograd
Translokacija t(8;21)(q22;q22) je jedna od najèešæih citogenetskih abnormalnosti u
akutnoj mijeloidnoj leukemiji. Preko 90% sluèajeva korelira sa dijagnozom AML M2, a
reðe se nalazi u AML M1 i AML M4. Na hromozomu 8 prekid se dešava u okviru ETO
gena a na hromozomu 21 u okviru AML1 gena pri èemu se formira fuzioni AML1/ETO
gen koji je lociran na derivatu hromozoma 8. Posebno su interesantne kompleksne
translokacije gde pored hromozoma 8i21uèestvuje i treæi hromozom.
U Laboratoriji za citogenetiku Instituta za hematologiju KCS u periodu od januara 1990.
do septembra 2004. godine, bilo je 47 AML pacijenata sa t(8;21)(q22;q22). Meðu njima
je svega 3 pacijenta sa kompleksnim translokacijama gde su, pored hromozoma 8 i 21
ukljuèeni sledeæi regioni: 3p11, 5q13 i 9q34.
Od 47 pacijenata sa t(8;21)(q22;q22) 40 je bilo sa dijagnozom AML M2, 5 sa AML M4 i
2 sa AML M1. 24 pacijenta su imala t(8;21) kao solo aberaciju a kod ostalih su
detektovane dodatne citogenetske aberacije. Najèešæa dodatna aberacija je gubitak Y
hromozoma i ona je prisutna kod 15 pacijenata.
Iako je kod pacijenata sa varijantnim tipom translokacije t(8;V;21) došlo do
kompleksnijih promena na nivou hromozoma, derivat hromozoma 8 je na citogenetskom
nivou ostao intaktan. Kako se kod ovih pacijenata razvio isti tip hematološkog
maligniteta kao i kod standardne t(8;21)(q22;q22), najverovatnije struktura fuzionog
AML1/ETO gena, koji je glavni leukemogeni faktor, nije narušena.
TRANSLOCATION t(8;21)(q22;q22) AND ITS VARIANTS IN ACUTE
MYELOID LEUKEMIA
Translocation t(8;21) is one of the most common cytogenetic abnormalities found in
AML. More then 90% of all cases found are in correlation with AML-M2, rarely with
AML-M1 and M4. Breakpoint on chromosome 8 is in the region of ETO gene, while on
chromosome 21 it is in the region of AML1 gene. As a result of translocation, new fusion
gene called AML1/ETO is formed, and located on derivate of chromosome 8. Specially
interesting are complex translocations in which besides chromosomes 8 and 21, third
chromosome is involved.
Since January 1990. until September 2004. in cytogenetic laboratory of Institute of hematology
KCS we had 47 patients with AML who had t(8;21). Among them only three
patients had complex translocations, which involved following chromosomes and their
regions: 3p11, 5q13 and 9q34.
In this group of 47 patients with t(8;21), 40 had diagnosis of AML-M2, five had
AML-M4 and two had AML-M1. Twenty four patients had t(8;21) as the only aberration,
while the other in this group had additional cytogenetic aberrations. The most common
additional aberration, found in 15 patients, was the lost of chromosome Y.
Despite the fact that patients with variable type of translocations had more complex
changes at chromosomal level, on cytogenetic level derivate of chromosome 8 stayed intact.
Most probably the structure of fusion gene AML1/ETO, which was the main
leucogenic factor, was not changed. That could be the explanation why these patients had
the same type of hematological malignancy as the one with standard translocation
t(8;21).