Vascular stenosis in a child with visual pathway glioma treated with bevacizumab: a case report and review of literature.

BACKGROUND: Bevacizumab (BVZ) is a vascular endothelial growth factor inhibitor that has been widely accepted since its introduction into the cancer pharmacopoeia. Anecdotal reports suggested improvements in vision in children with visual pathway glioma. CASE PRESENTATION: We report a boy with visual pathway glioma whose vision had deteriorated significantly on vincristine and carboplatin, to the point that he was registered blind. Following bevacizumab therapy, there was a dramatic improvement in vision with reduction in tumour volume. However, following 20 doses of BVZ given over 19 months, he developed a significant cerebrovascular stenosis. CONCLUSION: The BVZ-induced cerebrovascular diseases in children are extremely rare but potentially serious. Importantly, stenosis has not been previously described in literature.

MRI capture of intermittent ventriculomegaly in a patient with ventriculo-peritoneal shunt.

Intermittent change in ventricular size in patients with ventriculo-peritoneal shunts is a recognised complication but definitive imaging evidence is rare. We report a 3 years old boy with a medullary astrocytoma and ventriculo-peritoneal shunt placement who demonstrated intermittent ventriculomegaly during a single MRI scan.

Hypertrophic Obstructive Cardiomyopathy in An Infant With Hemophagocytic Lymphohistiocytosis; Answer to a Riddle.

Familial hemophagocytic lymphohistiocytosis (FHLH) is a hereditary hyperinflammatory condition with T-cell and macrophage activation. Treatment consists of immunosuppressive therapy plus bone marrow transplantation. Cardiac manifestations of FHLH were scarcely mentioned in the literature with conflicting pathophysiological explanations. We report a case of hypertrophic obstructive cardiomyopathy associated with FHLH. Guided by such a case, a clear vision regarding the real cause is thought to be obtained in the cloudy landscape of pathophysiology.

Thiamine responsive megaloblastic anemia: the puzzling phenotype.

BACKGROUND: Thiamine responsive megaloblastic anemia (TRMA) is characterized by a triad of megaloblastic anemia, non-type 1 diabetes mellitus and sensorineural deafness. Other clinical findings have been described in few cases. The SLC19A2 gene on chromosome 1q 23.3 is implicated in all cases with TRMA. Our aim is to discuss the clinical manifestations of all Omani children diagnosed with TRMA and determine genotype-phenotype relationship. PROCEDURE: Clinical and laboratory data of all patients diagnosed in Oman were retrospectively collected. Mutation analysis of affected families was conducted using two Microsatellite markers. Genotyping was performed with fluorescent-labeled PCR primers. To define the deletion breakpoint region, PCR reactions were carried out using different primer pairs located at the introns 3 and 3'-untranslated region with Expand Long Template PCR kit. RESULTS: A total of six children have been diagnosed with this syndrome. They were five females and one male. They all presented with sensorineural deafness at birth while the age of anemia presentation ranged between 6 weeks to 19 months. They all belong to same family with complex interfamilial marriages and presented with the typical triad. Of interest is the very rare presentation of one patient with Uhl cardiac anomaly (total absence of right ventricular myocardium with apposition of endocardium and pericardium) that has never been described before in patients with TRMA. All patients have a novel large deletion of 5,224 bp involving exons 4, 5, and 6 of SLC19A2. CONCLUSIONS: TRMA is a disease of expanding phenotypic spectrum with poor genotype-phenotype correlation.

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. Aim was to assess the efficacy of a lower initial dose of HU and cautious dose escalation regimen in patients with SCD. METHODS: We assessed 161 patients with SCD on HU, at Sultan Qaboos University Hospital (SQUH), Muscat, Oman, retrospectively from 1998 to 2008 and prospectively from 2009 to 2011. Starting dose of HU was 10-12 mg/kg/day, adjusted based on response or side effects. Patients were divided into two groups according to the dose of HU (10-15.9 mg/kg/day and 16-26 mg/kg/day). RESULTS: Nineteen patients were excluded for various reasons. Forty-four children were in the low-dose group and 98 were in the high-dose group. There was significant reduction in the annual number of admissions due to vaso-occlusive crisis in both groups (P < 0.001). However, the difference between the two groups was statistically insignificant (P > 0.05). In addition, there was an observed clinical improvement regarding the acute chest syndrome (ACS). Both groups had comparable significant improvements in their laboratory markers [e.g., hemoglobin (Hb), Mean Corpuscular Volume (MCV), and absolute neutrophil count (ANC)]. All 142 patients tolerated the treatment well. Reversible toxicities occurred in both low- and high-dose groups. CONCLUSION: In SCD patients, low-dose regimen of HU is a feasible option that ensured safety and yet did not affect efficacy.

Brain is not always the last fortress; osteosarcoma with large brain metastasis.

Osteosarcomas are the most common malignant primary bone tumors in children and adolescents. Brain metastases of osteosarcoma are very rare and carry a dismal prognosis. We report a case of chondroblastic osteosarcoma of right humerus presented with right frontal lobe metastasis in a 10-year-old girl with small pulmonary lesions.

Coexistence of sickle cell disease and severe congenital neutropenia: first impressions can be deceiving.

We report an Omani family in whom the propositus had a rare coexistence of sickle cell disease and severe congenital neutropenia associated with a mutation in ELANE. In contrast to his siblings with sickle cell disease, the severity of HbSS-associated complications such as painful crises and acute chest syndrome was significantly reduced. His course of the disease had markedly worsened after initiating G-CSF therapy. These clinical observations suggest that neutropenia may ameliorate inflammatory responses and thus display a modulating factor with respect to the clinical course of sickle cell disease.

dRTA and hemolytic anemia: first detailed description of SLC4A1 A858D mutation in homozygous state.

Mutations in the anion exchanger 1 (AE1) gene encoding the erythroid and kidney anion (chloride-bicarbonate) exchanger 1 may result in familial distal renal tubular acidosis (dRTA) in association with membrane defect hemolytic anemia. Seven children presenting with hyperchloremic normal anion gap metabolic acidosis, failure to thrive, and compensated hemolytic anemia were studied. Analysis of red cell AE1/Band 3 surface expression by Eosin 5'-maleimide (E5M) was performed in patients and their family members using flow cytometry. Genetic studies showed that all patients carried a common SLC4A1 mutation, c.2573C>A; p.Ala858Asp in exon 19, found as homozygous (A858D/A858D) mutation in the patients and heterozygous (A858D/N) in the parents. Analysis by flowcytometry revealed a single uniform fluorescence peak, with the mean channel fluorescence (MCF) markedly reduced in cases with homozygous mutation, along with a left shift of fluorescence signal but was only mildly reduced in the heterozygous state. Red cell morphology showed striking acanthocytosis in the homozygous state [patients] and only a mild acanthocytosis in heterozygous state [parents]. In conclusion, this is the first description of a series of homozygous cases with the A858D mutation. The E5M flowcytometry test is specific for reduction in the Band 3 membrane protein and was useful in conjunction with a careful morphological examination of peripheral blood smears in our patient cohort.

Novel PKLR missense mutation (A300P) causing pyruvate kinase deficiency in an Omani Kindred-PK deficiency masquerading as congenital dyserythropoietic anemia.

We report herein a child with transfusion-dependent chronic anemia, the cause of which was difficult to establish because of his transfusion dependency. The clinical and laboratory features suggested a chronic nonspherocytic hemolytic anemia (CNSHA) with bone marrow features suggestive of congenital dyserythropoietic anemia (CDA). DNA studies, however, revealed the underlying condition to be due to a novel mutation in the PKLR gene responsible for pyruvate kinase deficiency (PKD). Molecular investigations by a targeted next-generation sequencing (t-NGS) using a custom panel of 71 genes involved in the red blood cell (RBC) disorders revealed that the patient was homozygous for a novel missense mutation c.898G>C, p.Ala300Pro, whereas both his parents were heterozygous for the same mutation.

Severity ranking of non-deletional alpha thalassemic alleles: insights from an Omani family study.

In an Omani family, four different alpha thalassemic alleles, one single-gene deletional (-α(3.7) ) and three non-deletional forms (α(TSaudi) , α(Δ5nt) , and α(ΔG) ), interact in various combinations and result in two distinct hematological phenotypes, with and without HbH inclusions. After excluding the presence of potential genetic modifiers, viz associated ß-thalassemic alleles or functional alpha hemoglobin stabilizing protein (AHSP) polymorphisms, we observed that only the genetic combinations involving α(TSaudi) mutation are associated with HbH inclusions (a marker of degree of α/ß-chain imbalance) and high reticulocyte count (a marker of ongoing hemolysis). Overall, the α(TSaudi) mutation is associated with a more severe α-globin deficiency than the other two (α(Δ5nt) and α(ΔG) ) non-deletional α(0) thalassemic mutations. The likely molecular explanation is that the compensatory increase in the linked α1 globin gene expression is much more compromised in cases with α(TSaudi) mutation.

Case Study: using a continuous glucose monitoring system in a patient with diabetes and beta-thalassemia hemoglobinopathy.

Optimum glycemic control is extremely important in patients with diabetes mellitus to avoid long-term complications. Glycemic control relies mainly on the use of hemoglobin A1c, which unfortunately showed inaccurate results in patients with hemoglinopathies. The authors describe a case of beta-thalassemia with poorly controlled diabetes mellitus that has misleading low levels of HbA1c. The use of a continuous glucose monitoring system was useful in documenting her poor glycemic control, with prolonged periods of hyper- and hypoglycemia. Based on these results, her insulin regimen was adjusted and the blood glucose levels were greatly improved throughout and the patient was able to meet her target blood glucose range (72-140 mg/dL [4-7.8 mmol/L]) in 70% of the time.

KMT2A-MLLT3 AML Masquerading as JMML may Disguise Fatal Leukemia.

We present a mortality case showcasing t(9;11)-positive acute myeloid leukemia/juvenile myelomonocytic leukemia (AML/JMML) overlap to shed light on this lethal molecular subtype of AML. In this case, the flawed assumption that JMML was to blame impeded the prompt undertaking of appropriate treatment for AML in our 14-month-old patient. This article aims to scrutinize the catastrophic sequel of such an overlap in leukemia and refutes the contemporary diagnostic methods.

Invasive candidal laryngitis as a manifestation of cyclic neutropenia in an Omani infant.

Cyclic neutropenia is a congenital episodic defect in the development of neutrophils in the bone marrow. It is usually diagnosed late in infancy as it generally takes several cycles of neutropenia before the condition is suspected. These patients often have recurrent mild infectious episodes, but may develop life-threatening bacterial infections; however, they are unlikely to develop fungal infections as the neutropenia is usually self-limiting and of short duration. The authors report the case of an 8-month-old Omani female infant with cyclic neutropenia presenting as severe fungal (Candida) invasive laryngitis, needing life-saving tracheostomy and i.v. antifungal treatment.

Human Parvovirus B19 in Children with Sickle Cell Disease; Poking the Spleen.

Parvovirus is a known culprit of transient red cell aplasia (TRCA) in children with sickle cell disease (SCD). Few reports have previously described the association between the virus and acute splenic sequestration crisis (ASSC) in the same patient. Here, we are shedding light on such a potentially serious combination by reporting two cases of siblings with SCD complicated with concurrent ASSC and TRCA and presenting a review of the relevant literature.

Echocardiography in PICU: when the heart sees what is invisible to the eye.

OBJECTIVE: Echocardiography has become an indispensable bedside diagnostic tool in the realm of pediatric intensive care units (PICU). It has proven to be an influential factor in the formula of clinical decision-making. This study aimed to delineate the impact of echocardiography on the management of critically ill pediatric patients in the PICU at Sultan Qaboos University Hospital, Oman. METHOD: This was a retrospective cohort study conducted in a five-bed PICU. Patients admitted to the PICU from January of 2011 to December of 2012 were reviewed. Those who have undergone bedside echocardiography during their ICU stay were recruited. Electronic patient record was used as data source. RESULTS: Over a-24-month period, 424 patients were admitted in this PICU. One hundred and one clinically indicated transthoracic echocardiograms were performed. 81.8% of these presented new findings (n=82) that significantly impacted the clinical decision of patient management, namely, alteration in drug therapy and procedure, whereas no difference in the management was yielded in the remaining 17.8% of the studied cases. CONCLUSIONS: Echocardiography had a significant impact on the management of PICU patients. Such salutary effect was consequently reflected on the outcome. Pediatric intensivists are encouraged to acquire such bedside skill.