Publications by authors named "Vajira H W Dissanayake"

Article Synopsis
  • - The study analyzed genetic polymorphisms in Sri Lankans to understand variations in responses to immunomodulator drugs used for autoimmune diseases and blood cancers, using data from 670 participants.
  • - Among the most common variants, SLC19A1 showed a major presence at 63.3%, while others had varying frequencies, indicating significant genetic diversity compared to global populations.
  • - Notably, some variants like MTHFR were less prevalent in Sri Lankans compared to other groups, highlighting unique genetic profiles that could influence drug efficacy and safety in this population.
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  • This case report describes the first documented instance of a child having both mitochondrial encephalomyopathy (a condition affecting muscles and the brain) and nemaline myopathy (a muscle disorder), highlighting their coexistence.
  • An 11-year-old Sri Lankan boy, previously healthy, experienced acute neurological symptoms, elevated lactate levels, and imaging results indicative of an acute brain infarction, leading to genetic testing that confirmed both conditions.
  • The child's treatment included supportive care, antiepileptics, and supplements, with ongoing monitoring, underscoring the importance of genetic diagnosis for effective management and family counseling.
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  • Anti-cancer drug therapy is crucial for treating cancer but can vary in effectiveness and safety among individuals due to genetic differences, a factor that is not often addressed in Sri Lanka’s treatment guidelines.
  • This study investigates pharmacogenomic variants in Sri Lankans by analyzing data from 541 individuals to identify how these genetic variations impact responses to specific anti-cancer drugs.
  • Results show that certain genetic variants have notable frequencies in the Sri Lankan population, potentially guiding personalized therapy to enhance treatment outcomes.
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Background: BRCA1 and BRCA2 pathogenic variants account for 90% of hereditary breast malignancies, incurring a lifetime breast cancer risk of 85% and 40-45% respectively, in affected individuals. Well-resourced health care settings offer genetic counselling and genetic screening for susceptible individuals, followed by intense breast cancer surveillance programmes for those identified at high risk of breast cancer. Such high standards of care are not available in countries with limited resources.

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Background: Patients, families, the healthcare system, and society as a whole are all significantly impacted by rare diseases (RDs). According to various classifications, there are currently up to 9,000 different rare diseases that have been recognized, and new diseases are discovered every month. Although very few people are affected by each uncommon disease individually, millions of people are thought to be impacted globally when all these conditions are considered.

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Background: Skeletal dysplasias are a diverse group of rare disorders in the chondro-osseous tissue that can have a significant impact on patient's functionality. The worldwide prevalence of skeletal dysplasias at birth is approximately 1:5000 births. To date, disease burden and trends of skeletal dysplasias in the Sri Lankan population have not been described in any epidemiological study.

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Background: Spontaneous coronary artery dissection (SCAD) is increasingly diagnosed as one of the infrequent causes of acute coronary syndrome. Almost no cause was identified in half of the cases. Here, we report a rare case of spontaneous coronary artery dissection with leucoencephalopathy (SCADLE) associated with a mutation of the thrombospondin Type 1 domain containing 1 (THSD1) gene.

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Background: Next-Generation Sequencing (NGS)-based testing in cancer patients has led to increased detection of variants of uncertain significance (VUS). VUS are genetic variants whose impact on protein function is unknown. VUS pose a challenge to clinicians and patients due to uncertainty regarding their cancer predisposition risk.

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Introduction: Rare diseases (RD) are a health priority worldwide, overall affecting hundreds of millions of people globally. Early and accurate diagnosis is essential to support clinical care but remains challenging in many countries, especially the low- and medium-income ones. Hence, undiagnosed RD (URD) account for a significant portion of the overall RD burden.

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Introduction: Leber hereditary optic neuropathy is a genetic disease of mitochondrial inheritance characterized by bilateral irreversible vision loss, predominantly affecting males. We report the first genetically authenticated Sri Lankan case of Leber hereditary optic neuropathy, illustrating its characteristic features of male predominance and variable penetrance.

Case Presentation: A 15-year-old previously healthy Sri Lankan boy presented with painless progressive vision loss in his right eye, followed by vision loss in his left eye within 3 months.

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Recent studies suggest that chromosomal polymorphic variations are associated with infertility. A systematic review of chromosomal polymorphisms in assisted reproduction found an association with higher rates of miscarriage. Aim of this study is to analyse the influence of specific types or number of chromosomal polymorphic variations on reproductive outcomes of couples undergoing ICSI treatment.

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Biallelic pathogenic variants in the genes encoding the dolichol-phosphate mannose synthase subunits (DPM) which produce mannosyl donors for glycosylphosphatidylinositols, N-glycan and protein O- and C-mannosylation, are rare causes of congenital disorders of glycosylation. Pathogenic variants in DPM1 and DPM2 are associated with muscle-eye-brain (MEB) disease, whereas DPM3 variants have mostly been reported in patients with isolated muscle disease-dystroglycanopathy. Thus far, only one affected individual with compound heterozygous DPM3 variants presenting with myopathy, mild intellectual disability, seizures, and nonspecific white matter abnormalities (WMA) around the lateral ventricles has been described.

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Background: Iron overload (IO) is a complication in transfusion dependent beta thalassaemia (TDT). Pathogenic variants in genes involving iron metabolism may confer increased risk of IO. The objective of this study was to determine the magnitude of the cardiac and hepatic IO and determine whether pathogenic variants in HFE, SLC40A1 and TFR2 genes increase the risk of IO in a cohort of TDT patients in Sri Lanka.

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Introduction: Maturity models assess the snapshot view of an organization and simultaneously guides the organization to advance on a road map towards ultimate levels of maturity. The health industry has recently embraced maturity models as a tool to improve the management of health information systems. Most electronic health information systems in Sri Lanka need assessment and monitoring and can benefit vastly by adopting maturity models.

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Objective: Although linkage studies have been utilized for the identification of variants associated with cancer in the world, little is known about their role in non BRCA1/2 individuals in the Sri Lankans. Hence we performed linkage analysis to identify susceptibility loci related to the inherited risk of cancer in a cohort of Sri Lankans affected with hereditary breast cancer. The Illumina global screening array having 654,027 single nucleotide polymorphism markers was performed in four families, in which at least three individuals within third degree relatives were affected by breast cancer.

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The formation of the digits is a tightly regulated process. During embryogenesis, disturbance of genetic pathways in limb development could result in syndactyly; a common congenital malformation consisting of webbing in adjacent digits. Currently, there is a paucity of knowledge regarding the exact developmental mechanism leading to this condition.

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Objectives: Tamoxifen is considered to be the most widely used adjuvant therapy for hormone receptor positive breast cancer in premenopausal women. However, it is reported that nearly 30% of patients receiving tamoxifen therapy have shown reduced or no benefits. This may be due to the high inter-individual variations in the CYP2D6 gene that is involved in tamoxifen metabolism.

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Purpose: Widespread, quality genomics education for health professionals is required to create a competent genomic workforce. A lack of standards for reporting genomics education and evaluation limits the evidence base for replication and comparison. We therefore undertook a consensus process to develop a recommended minimum set of information to support consistent reporting of design, development, delivery, and evaluation of genomics education interventions.

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Background: Collagen VI-related dystrophies are a subtype of congenital muscular dystrophy caused by pathogenic variants in COL6A1, COL6A2 or COL6A3 genes affecting skeletal muscles and connective tissue. The clinical phenotype ranges from the milder Bethlem myopathy to the severe Ullrich congenital muscular dystrophy (UCMD). Herein, we report the first consanguineous Sri Lankan family with two children affected with UCMD due to a novel variant in the COL6A1 gene.

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Myelodysplastic Syndromes (MDS) are hematological clonal disorders. Bone marrow (BM) mesenchymal stem cells (MSCs) interact with the haematopoietic stem and progenitor cells (HSPCs) to regulate haematopoiesis. We studied the genetic variation profiles of BM derived CD34 HSPCs and MSCs of same patient in a South Asian de novo MDS cohort with 20 patients.

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A Sri Lankan male child with supraorbital hyperostosis, broad nasal bridge, small mandible, severe kyphoscoliosis, distal joint contractures of the hands and long second and third toes is described. A hemizygous pathogenic variant in exon 22 of the filamin A (FLNA) gene [NM_001110556.1: c.

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Rubinstein-Taybi syndrome (RSTS) is an autosomal dominant disorder, caused by loss-of-function variants in CREBBP or EP300. Affected individuals present with distinctive craniofacial features, broad thumbs and/or halluces, and intellectual disability. RSTS phenotype has been well characterized in individuals of European descent but not in other populations.

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Next-generation sequencing of Sri Lankan families with inherited cancer syndromes resulted in the identification of five BRCA2 variants of unknown clinical significance. Interpreting such variants poses significant challenges for both clinicians and patients. Using a mouse embryonic stem cell-based functional assay, we found I785V, N830D, and K2077N to be functionally indistinguishable from wild-type BRCA2.

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Turner syndrome (TS) is a common multiple congenital anomaly syndrome resulting from complete or partial absence of the second X chromosome. In this study, we explore the phenotype of TS in diverse populations using clinical examination and facial analysis technology. Clinical data from 78 individuals and images from 108 individuals with TS from 19 different countries were analyzed.

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