Position paper: Challenges and specific strategies for constitutional mismatch repair deficiency syndrome in low-resource settings.

Germline biallelic mutations in one of the mismatch repair genes, mutS homolog 2, mutS homolog 6, mutL homolog 1, or postmeiotic segregation increased 2, result in one of the most aggressive cancer syndromes in humans termed as constitutional mismatch repair deficiency (CMMRD). Individuals with CMMRD are affected with multiple tumors arising from multiple organs during childhood, and these individuals rarely reach adulthood without specific interventions. The most common tumors observed are central nervous system, hematological, and gastrointestinal malignancies.

Improving Cancer Care for Children in the Developing World: Challenges and Strategies.

Cancer is a global health problem particularly in developing countries where the burden of cancer is ever increasing and claiming the lives of about 100,000 children under the age of 15 years every year. Majority of these occur in the Low and Middle Income Countries (LMICs) where 90% of world children live. Contributing factors to this trend is the reduction of communicable diseases and emergence of new infections, improvement of nutrition and socio-economic conditions, industrialization and urbanization.

Childhood acute lymphoblastic leukemia in the Middle East and neighboring countries: a prospective multi-institutional international collaborative study (CALLME1) by the Middle East Childhood Cancer Alliance (MECCA).

Background: Little is known about childhood ALL in the Middle East. This study was undertaken by MECCA as initial efforts in collaborative data collection to provide clinical and demographic information on children with ALL in the Middle East.

Procedure: Clinical and laboratory data for patients with ALL between January 2008 and April 2012 were prospectively collected from institutions in 14 Middle East countries and entered into a custom-built-database during induction phase.

Optimizing Hydroxyurea use in children with sickle cell disease: low dose regimen is effective.

Background And Objectives: Hydroxyurea (HU) is the standard treatment for severely affected children with sickle cell disease (SCD). Starting dose is 15-20 mg/kg/day that can be escalated up to 35 mg/kg/day. Ethnic neutropenia is common in this area of the world that requires judicious usage of myelosuppressive drugs.

Transcranial Doppler ultrasonography in sickle cell disease: a study in Omani patients.

Changes on Transcranial Doppler (TCD) ultrasonography have been proposed as significant predictors of cerebrovascular complications in sickle cell disease (SCD). However, consensus with regards to the TCD criteria to recognize abnormalities in cerebral vasculature is lacking. We studied the TCD characteristics of cerebral arteries among Omani patients with SCD and correlated them with cerebrovascular events.

Splenectomy for haematological disorders: a single center study in 150 patients from Oman.

Background: Haematological disorders, in particular sickle cell disease (SCD) and thalassaemia, are relatively common in Oman. We report our experience of splenectomy for haematological disorders and review the literature on splenectomy role in their management.

Objectives: To review our experience in the management of 150 patients with haematological disorders undergoing splenectomy with emphasis on indications and outcome.

Characterization of PRF1, STX11 and UNC13D genotype-phenotype correlations in familial hemophagocytic lymphohistiocytosis.

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare autosomal recessive lethal condition characterized by fever, cytopenia, hepatosplenomegaly and hemophagocytosis. The hallmark of FHL is defect apoptosis triggering and lymphocyte cellular cytotoxicity. Thus far three disease-causing genes (PRF1, UNC13D, STX11) have been identified.

Cytogenetic, morphological, and immunophenotypic patterns in Omani patients with de novo acute myeloid leukemia.

Chromosome aberrations observed at diagnosis are considered to be the most valuable prognostic factors in acute myeloid leukemia (AML). Some specific aberrations vary in frequency among different geographical areas and ethnic groups. There are only limited studies on the role of such variability in AML patients.

Novel spectrum of perforin gene mutations in familial hemophagocytic lymphohistiocytosis in ethnic Omani patients.

Familial hemophagocytic lymphohistiocytosis (FHL) is an autosomal recessive immune disorder, characterized by fever, hepatosplenomegaly, pancytopenia, hypertriglyceridemia, hypofibrinogenemia, markedly elevated levels of inflammatory cytokines, and impaired cytotoxic activity of lymphocytes. FHL is often fatal in early infancy. Histologic features include organ infiltration by activated macrophages and lymphocytes.

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.

Nature of bacteria found on some wards in Sultan Qaboos University Hospital, Oman.

This study aims to determine what objects lying in the hospital environment or brought in from outside contribute to the introduction of bacteria associated with nosocomial infections. One hundred swab specimens collected from children's toys, sinks, door handles, telephone handsets and flowers brought into the hospital were plated on different culture media. Colonial growth on the media was purified and identified subsequently using standard bacteriological methods.

Incidence and outcome of severe hyponatremia in children and young adults: a single institution experience.

Objective: Our two main objectives are to assess the incidence and the outcome of severe hyponatremia in young hospitalized patients.

Method: We retrospectively reviewed the incidence and outcome of severe hyponatremiac (Na <125 mmol/l) inpatients less than 18 years of age, admitted as consecutive admissions during one calender year. Psuedohyponatremia and artifactual hyponatremia were excluded.

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.

An inframe perforin gene deletion in familial hemophagocytic lymphohistiocytosis is associated with perforin expression.

Familial hemophagocytic lymphohistiocytosis is an autosomal recessive disease of early childhood manifested by hypercytokinemia and organ infiltration of macrophages and activated lymphocytes, and it is characterized by a fulminant clinical course. The molecular mechanism underlying this disease appears to be a deregulation of apoptosis of activated T cells and macrophages. Approximately 20-40% of patients with familial hemophagocytic lymphohistiocytosis reported worldwide had a perforin gene mutation.

A community-based study of common hereditary blood disorders in Oman.

We assessed the prevalence of three common hereditary blood disorders (sickle-cell and beta-thalassaemia traits and glucose 6-phosphate dehydrogenase deficiency) among the Omani population. We interviewed a representative sample of 6103 Omani households and blood samples from 6342 children aged 0-5 years were collected. About 27% of Omani males had inherited glucose-6-phosphate dehydrogenase deficiency (compared with 11% of females) while countrywide prevalence rates for the sickle-cell and beta-thalassaemia traits were estimated to be 5.

Relapsed acute leukemia in children: Oman experience.

Acute leukemia (AL) is the most common malignancy in children in Oman. It accounts for over one-third of all childhood cancers, most of which (approximately 75%) are acute lymphoblastic leukemia (ALL). Over a decade, a total of 128 cases of childhood acute leukemia have been diagnosed and managed at Paediatric Haematology/Oncology Unit, Sultan Qaboos University Hospital, which is the national referral center of pediatric leukemia cases.

Ten-year prospective study (clinical spectrum) of childhood Guillain-Barré syndrome in the Arabian peninsula: comparison of outcome in patients in the pre- and post-intravenous immunoglobulin eras.

A prospective study of Guillain-Barré syndrome from January 1992 to December 2001 was undertaken. Intravenous immunoglobulins were used in all patients. All patients were followed up until complete recovery.

Clinical and genetic studies of familial hemophagocytic lymphohistiocytosis in Oman: need for early treatment.

Hemophagocytic lymphohistiocytosis (HLH) embraces the frequently indistinguishable conditions of familial hemophagocytic lymphohistiocytosis (FHL) and virus-associated hemophagocytic syndrome (VAHS). Without therapy FHL is invariably fatal, but successful therapy, including chemotherapy and immunotherapy followed by bone marrow transplantation (BMT), has been presented. To clarify the outcome of HLH in a developing country, with regard to clinical, laboratory, and genetic features, a nationwide study on all patients diagnosed with HLH in Oman during the 5-year period 1997-2001 was performed.

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.

Pulsed high-dose dexamethasone therapy in children with chronic idiopathic thrombocytopenic purpura.

The effectiveness of pulsed high-dose oral dexamethasone therapy in children with refractory chronic idiopathic thrombocytopenic purpura (ITP) is evaluated. Thirteen children with severe chronic ITP were enrolled in the study from an outpatient pediatric hematology clinic (ages 2-14 years), 5 boys and 7 girls. They did not maintain a response to other forms of therapy (IVIg, Anti-D, conventional steroids, danazol) and one girl relapsed after splenectomy.

Visceral leishmaniasis and haemophagocytic syndrome in an Omani child.

The paper reports the case of a previously healthy 4-year-old-girl who presented with pallor, fever and hepatosplenomegaly. Laboratory findings included pancytopenia, hypertriglyceridemia and hyperferritinemia. Initial diagnosis of kala-azar could not be confirmed because of the absence of clinical evidence, negativity of bone marrow aspiration or specific serology for visceral leishmaniasis.

Orbital involvement in sickle cell disease: a report of five cases and review literature.

Purpose: To present five cases of orbital infarction in sickle cell disease and review relevant literature.

Method: We reviewed the hospital records of 5 patients with sickle cell disease who developed a periorbital swelling during a vaso-occlusive crisis and were managed at our hospital between April 1992 and June 2000.

Results: The 5 patients (4 with homozygous sickle cell disease and 1 with sickle cell-beta-thalassaemia disease) were aged 6-15 years with a history of multiple admissions for vaso-occlusive crises.