Cytogenetic profile of childhood acute lymphoblastic leukemia in Oman.
BACKGROUND
Chromosomal abnormalities have important diagnostic and prognostic significance in acute lymphoblastic leukemia (ALL). The purpose of this study was to define and classify the frequency and type of chromosomal abnormalities among newly diagnosed children with ALL and compare the results with those reported from other geographical regions of the world.


METHODS
Bone marrow chromosomal studies with GTG banding were performed in untreated ALL pediatric patients aged from 7 days to 14 years.


RESULTS
Among Omani children examined with ALL, 47 (81%) patients yielded results, with 26 (55.3%) showing an abnormal karyotype [10 (21.3%) pseudodiploid, 2 (4.3%) hypodiploid and 14 (29.7%) hyperdiploidy] and 21 (44.6%) had normal diploidy. Structural abnormalities were observed in 16 (34%), of which 11 (23.4%) cases were translocations, the most frequent being t(9;22) observed in three (6.4%) of our patients. Uncommon translocations such as t(9;15)(p11;q10), t(3;6)(p12;q11), t(1;6)(?31;?q23), t(1;19)(q12;q12), der(18)t(12;18)(q11;p11), and other structural aberrations add(2)(q22), add(6)(q16), add(18)(q22), add(14)(q32) along with deletions del(10)(q22), del(12)(p11), del(12)(p12), del(18)(q11) were also observed.


CONCLUSIONS
The study showed a good correlation and concordance between the ploidy distribution by cytogenetics and flow cytometry. The patterns of chromosomal anomalies in our patients showed some variations in the frequency of aberrations reported. It is therefore necessary that newer techniques like fluorescence in situ hybridization (FISH) along with reverse transcriptase polymerase chain reaction (RT-PCR) and spectral karyotyping will help us identify chromosomal aberrations not detected by conventional cytogenetic methods in the near future. To our knowledge, this is the first report from the Middle East of a cytogenetic study on childhood ALL.
Udayakumar
Achandira Muthappa
AM
Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, and Hospital, Muscat, Sultanate of Oman. udaya@squ.edu.om
Bashir
Wafa Ahmed
WA
Pathare
Anil Vasant
AV
Wali
Yasser Ahmed
YA
Zacharia
Mathew
M
Khan
Ashfaq Ahmed
AA
Soliman
Heba
H
Al-Lamki
Zakia
Z
Raeburn
John Alexander
JA
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D003582:Cytogenetics; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009850:Oman; D011003:Ploidies; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology