Importance of FISH combined with Morphology, Immunophenotype and Cytogenetic Analysis of Childhood/ Adult Acute Lymphoblastic Leukemia in Omani Patients.

Genetic changes associated with acute lymphoblastic leukemia (ALL) provide very important diagnostic and prognostic information with a direct impact on patient management. Detection of chromosome abnormalities by conventional cytogenetics combined with fluorescence in situ hybridization (FISH) play a very significant role in assessing risk stratification. Identification of specific chromosome abnormalities has led to the recognition of genetic subgroups based on reciprocal translocations, deletions and modal number in B or T-cell ALL. In the last twelve years 102 newly diagnosed childhood/adult ALL bone marrow samples were analysed for chromosomal abnormalities with conventional G-banding, and FISH (selected cases) using specific probes in our hospital. G-banded karyotype analysis found clonal numerical and/or structural chromosomal aberrations in 74.2% of cases. Patients with pseudodiploidy represented the most frequent group (38.7%) followed by high hyperdiploidy group (12.9%), low hyperdiploidy group (9.7%), hypodiploidy (<46) group (9.7%) and high hypertriploidy group (3.2%). The highest observed numerical chromosomal alteration was high hyperdiploidy (12.9%) with abnormal karyotypes while abnormal 12p (7.5%) was the highest observed structural abnormality followed by t(12;21)(p13.3;q22) resulting in ETV6/RUNX1 fusion (5.4%) and t(9;22)(q34.1;q11.2) resulting in BCR/ABL1 fusion (4.3%). Interestingly, we identified 16 cases with rare and complex structural aberrations. Application of the FISH technique produced major improvements in the sensitivity and accuracy of cytogenetic analysis with ALL patients. In conclusion it confirmed heterogeneity of ALL by identifying various recurrent chromosomal aberrations along with non-specific rearrangements and their association with specific immunophenotypes. This study pool is representative of paediatric/adult ALL patients in Oman.

Postvaricella thrombosis-report of two cases and literature review.

Varicella (chickenpox) is a common disease of childhood, caused by varicella-zoster virus. Postviral thromboembolism is a rare complication of varicella-zoster virus in childhood. We describe 2 children who developed lower limb deep venous thrombosis shortly after varicella infection, along with a review of 130 previously reported cases.

Identification of prognosis markers in pediatric high-risk acute lymphoblastic leukemia.

Gene expression profiling may improve the understanding of the biology behind relapse in pediatric acute lymphoblastic leukemia. Using suppression subtractive hybridization (SSH), cDNA concatenated sequencing (CCS), and reverse transcriptase real-time quantitative polymerase chain reaction (RT-RQ-PCR) on high-risk patient samples with nondeterminant chromosomal translocation, the authors identified 3 genes that were significantly overexpressed in the nonrelapsed patients: the calcium/calmodulin-dependent serine protein kinase (CASK), subunit 2 of the cofactor required for SP1 transcriptional activation (CRSP2), and granzyme K (GZMK). The level of expression of these biomarkers may help identify patients with potentially good prognosis within a group otherwise at high risk of relapse.

Splenic function in Omani children with sickle cell disease: correlation with severity index, hemoglobin phenotype, iron status, and alpha-thalassemia trait.

The prevalence of functional asplenia in Omani children with sickle cell disease (SCD) has not been previously defined. In this study, the authors aim to compare the natural history of splenic dysfunction in their patients to other reports. The splenic function was studied in 72 Omani patients with sickle cell disease (50 homozygous for hemoglobin S (HbS-S), 11 double heterozygotes for HbS and beta(0)-thalassemia (HbS-beta(0)-thal), 5 HbS-beta(+)-thal, 5 patients with hemoglobin S-D disease, and 1 child with hemoglobin S oman trait) aged 4.8-16 years, using (99m)Tc-labeled tin colloid scintigraphy. The study revealed 4 groups according to their colloid uptake: group I included 20 patients (28%) with normal splenic function; group II, 6 patients (8%) with mild hyposplenism; group III, 20 (28%) with severe hyposplenism; and group IV, 26 (36%) patients with functional asplenia. Overall, more than 60% of them had preserved splenic function. Except for HbS-beta(+) patients, the developmental pattern of hyposplenism was not different among the different Hb phenotypes. Factors associated with preservation of spleen function in these patients were larger splenic size (p < .01), less clinical severity (p < .05), lower MCH (p < .01), higher HbF (p < .001), and presence of alpha-thalassemia trait (p < .05).