Hamidah Alias

Vincristine-induced vocal cord palsy: case report and review of the literature.

Vincristine-induced vocal cord paralysis is a rare but serious complication. We report 2 patients with acute lymphoblastic leukemia who developed progressive stridor during induction chemotherapy. There were no clinical features of peripheral or autonomic neuropathy. Flexible laryngoscopy confirmed the diagnosis of bilateral vocal cord palsy; interestingly, the nerve conduction test revealed axonal motor neuropathy involving the median and common peroneal nerves in both patients. The first patient required prolonged ventilatory support necessitating unilateral cordectomy before extubation, whereas the second only required supplemental oxygen therapy. There was resolution of stridor in the first patient after cordectomy and gradual clinical improvement in the second. These cases illustrate that a high index of suspicion of vincristine-induced vocal cord palsy with prompt otolaryngology consultation for laryngoscopy is required in the diagnostic evaluation of a patient who has received vincristine.

Molecular study and genotype/phenotype correlation of β Thalassemia in Malaysia.

Introduction:  To study the ß‐gene mutations spectrum, the genotype/phenotype correlation, the modulatory effect of co‐inherited factors such as α‐gene mutations and of Xmn1 polymorphism in a large cohort of Malaysian patients.

Meta-analysis of gene expression in relapsed childhood B-acute lymphoblastic leukemia

BackgroundRelapsed pediatric B-acute lymphoblastic leukemia (B-ALL) remains as the leading cause of cancer death among children. Other than stem cell transplantation and intensified chemotherapy, no other improved treatment strategies have been approved clinically. Gene expression profiling represents a powerful approach to identify potential biomarkers and new therapeutic targets for various diseases including leukemias. However, inadequate sample size in many individual experiments has failed to provide adequate study power to yield translatable findings. With the hope of getting new insights into the biological mechanisms underpinning relapsed ALL and identifying more promising biomarkers or therapeutic targets, we conducted a meta-analysis of gene expression studies involving ALL from 3 separate studies.MethodBy using the keywords “acute lymphoblastic leukemia”, and “microarray”, a total of 280 and 275 microarray datasets were found listed in Gene Expression Omnibus database GEO and ArrayExpress database respectively. Further manual inspection found that only three studies (GSE18497, GSE28460, GSE3910) were focused on gene expression profiling of paired diagnosis-relapsed pediatric B-ALL. These three datasets which comprised of a total of 108 matched diagnosis-relapsed pediatric B-ALL samples were then included for this meta-analysis using RankProd approach.ResultsOur analysis identified a total of 1795 upregulated probes which corresponded to 1527 genes (pfp < 0.01; FC > 1), and 1493 downregulated probes which corresponded to 1214 genes (pfp < 0.01; FC < 1) respectively. S100A8 appeared as the top most overexpressed gene (pfp < 0.01, FC = 1.8) and is a potential target for further validation. Based on gene ontology biological process annotation, the upregulated genes were most enriched in cell cycle processes (enrichment score = 15.3), whilst the downregulated genes were clustered in transcription regulation (enrichment score = 12.6). Elevated expression of cell cycle regulators (e.g kinesins, AURKA, CDKs) was the key genetic defect implicated in relapsed ALL, and serve as attractive targets for therapeutic intervention.ConclusionWe identified S100A8 as the most overexpressed gene, and the cell cycle pathway as the most promising biomarker and therapeutic target for relapsed childhood B-ALL. The validity of the results warrants further investigation.

A case series of α-thalassemia intermedia due to compound heterozygosity for Hb Adana [HBA2: c179G>A (or HBA1); p.Gly60Asp] with other α-thalassemias in Malay families.

Abstract Hb Adana [HBA2: c179G>A (or HBA1); p.Gly60Asp] is a rare hemoglobin (Hb) variant due to a mutation at codon 59 of the α2- or α1-globin gene resulting in a glycine to aspartic acid substitution. Two siblings with a unique coinheritance of Hb Adana and Hb Constant Spring (Hb CS, α142, Term→Gln, TAA>CAA; HBA2: c.427 T>C) (αcodon 59α/αCSα), were compared phenotypically with another two siblings carrying the Hb Adana mutation and a 3.7 kb deletion (αcodon 59α/−α3.7). Although they all had α-thalassemia intermedia (α-TI), the former were clinically more severe than the latter. The first pair of siblings presented at a much younger age than the second pair and showed lower Hb levels and significant extramedullay hemopoiesis. Another case of a hydropic fetus as a result of Hb H/Hb Adana is also described. Their clinical phenotypes and hematological parameters are all presented for comparison.

Multiplexed genotyping of beta globin mutations with MALDI-TOF mass spectrometry ☆

BACKGROUND Beta thalassemia represents a great heterogeneity as over 300 mutations have been identified and each population at-risk has its own spectrum of mutations. Molecular characterization with high accuracy, sensitivity and economics is required for population screening and genetic counseling. METHODS We used the MALDI-TOF mass spectrometry (MS) platform to develop novel multiplex assays for comprehensive detection of 27 mutations in beta-thalassemia patients. Six multiplex assays were designed to detect 13 common known ß-mutations, namely CD41/42, CD71/72, IVS1-5, IVS1-1, CD26, IVS2-654, CAP+1, CD19, -28, -29, IVS1-2, InCD (T-G) and CD17; and 14 rare ß-mutations, i.e. InCD (A-C), CD8/9, CD43, -86, CD15, Poly A, Poly T/C, IVS2-1, CD1, CD35/36, CD27/28, CD16, CD37, and 619bpDEL in 165 samples. We compared the efficiencies of genotyping by MS and Amplification Refractory Mutation System (ARMS). Discrepant results were confirmed by sequencing analysis. RESULTS A total of 88.7% (260/293 allele) of MS and ARMS results was in agreement. More than fifty percent of the discrepant result was due to the false interpretation of ARMS results. Failed CD19 assay by MS method might be due to the assay design. The MS method detected 5 rare ß-mutations (CD15, CD35/36, CD8/9, Poly A and Poly T/C) presented in 13 alleles, which were not included in the ARMS screening panel. CONCLUSION We revealed that the MS method is a sensitive, high-throughput, highly automated, flexible, and cost-effective alternative to conventional ß-thalassemia genotyping methods.

ADAMTSL5 and CDH11: putative epigenetic markers for therapeutic resistance in acute lymphoblastic leukemia

ABSTRACT Background and objectives: DNA hypermethylation has been linked to poor treatment outcome in childhood acute lymphoblastic leukemia (ALL). Genes differentially methylated in the chemoresponsive pre-B-ALL compared to chemoresistant pre-B-ALL cases provide potential prognostic markers. Methods: DNA methylation profiles of five B-ALL childhood patients who achieved morphological complete remission (chemoresponsive) and five B-ALL patients who did not (chemoresistant) after induction treatments as well as four normal controls were compared on 27 000 CpG sites microarray chips. Subsequently, methylation-specific polymerase chain reaction (MSP) on selected hypermethylated genes was conducted on an additional 37 chemoresponsive and 9 chemoresistant B-ALL samples and 2 normal controls. Results: Both methods were found to be highly correlated. Unsupervised principal component analysis showed that the chemotherapy-responsive and -resistant B-ALL patients could be segregated from one another. Selection of segregated genes at high stringency identified two potential genes (CDH11 and ADAMTSL5). MSP analysis on the larger cohort of samples (42 chemoresponsive, 14 chemoresistant B-ALL samples and 6 normal controls) revealed significantly higher rates of hypermethylation in chemoresistant samples for ADAMTSL5 (93 vs. 38%; p = 0.0001) and CDH11 (79% vs. 40%, p < 0.01). All control cases remained unmethylated. Conclusion: Chemoresistant B-ALL patients are associated with increased methylation in ADAMTSL5 and CDH11. These findings need to be validated in a larger group of patients, and the functional biological and prognostic significance of differential methylation needs to be studied further.

Understanding Hospitalized Pediatric Cancer Patients’ Activities for Digital Games Design Requirements

This research aims to understand activities performed by pediatric cancer patients at the pediatric oncology ward. The focus of this study is to identify activities performed by patients during their stay in the hospital. 10 parents/guardians of the patients were interviewed to collect the information and description of activities performed by patients under their care. A thematic analysis was conducted to analyze all collected and transcribed interviews. The result shows that pediatric cancer patients express either positive or negative feeling. This feeling is based on their actions in the ward. The consequences from this are alarming: pediatric cancer patients are in high stress and depressed which would not be good for their health. The understanding of their activities in the ward can be transformed into design requirements for designing patient support games. Moreover, designers and developers of games can refer to this finding to compare their current existing games for cancer patients to the actual of the activities performed by the patients.

Using Data Mining Strategy in Qualitative Research

Analyzing qualitative data can be tedious if it is done manually. There are several techniques available to conduct qualitative research such as thematic analysis, grounded theory and content analysis amongst other techniques. The data collected from these techniques are usually huge in amount. Little has been done to apply data mining strategy to analyzes data gathered using qualitative methodology. In this paper, we present a work done to apply text mining technique to analyzes data gathered from interviews – unstructured data. The aim of this study is to develop patterns of pediatric cancer patient’s activities in the ward. The result shows a pattern that suggests patients are mostly playing video games while receiving treatment and when they feel bored in the ward. This proposes that data mining techniques can be used to provide an initial insight of the information gathered qualitatively.

Giant Cell Tumor of the Ribs and Aneurysmal Bone Cyst Presenting With Hemothorax in a Child

Giant cell tumor (GCT) is one of the most common tumors of bone and is the most common precursor of aneurysmal bone cysts (ABC). The clinical behavior of concurrent GCT and ABC can be very aggressive in children. GCT of the ribs, with or without ABC, is rarely seen in children. We report a case of an 8-year-old girl with GCT and associated ABC of the ribs who presented with sudden onset of chest pain and breathlessness due to a hemothorax. The patient was successfully treated by surgical resections and arterial embolization. She has remained well for 4 years after the initial surgery.

Gene mutations as emerging biomarkers and therapeutic targets for relapsed acute myeloid leukemia

It is believed that there are key differences in the genomic profile between adult and childhood acute myeloid leukemia (AML). Relapse is the significant contributor of mortality in patients with AML and remains as the leading cause of cancer death among children, posing great challenges in the treatment of AML. The knowledge about the genomic lesions in childhood AML is still premature as most genomic events defined in children were derived from adult cohorts. However, the emerging technologies of next generation sequencing have narrowed the gap of knowledge in the biology of AML by the detection of gene mutations for each sub-type which have led to the improvement in terms of prognostication as well as the use of targeted therapies. In this review, we describe the recent understanding of the genomic landscape including the prevalence of mutation, prognostic impact, and targeted therapies that will provide an insight into the pathogenesis of AML relapse in both adult and childhood cases.