Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item Development of a low cost semiquantitative polymerase chain reaction assay for molecular diagnosis of williams syndrome(Clinical Laboratory Publications, 2024) Ranaweera, D.M.; de Silva, D.C.; Samarasinghe, D.; Perera, S.; Kugalingam, N.; Samarasinghe, S.R.; Madushani, W.Y.; Jayaweera, H.H.E.; Gunewardene, S.; Muneeswaran, K.; Gnanam, V.S.; Chandrasekharan, N.V.BACKGROUND: Williams Beuren Syndrome (WBS) is a well-recognized and common genetic cause of congenital heart defects, developmental delay, hypercalcemia, and characteristic facial features. It is caused by a 1.5 - 1.8 Mb heterozygous deletion of chromosome 7q11.23 with loss of around 28 coding genes. The aim of this study was to develop a low-cost, semi-quantitative PCR (sqPCR) method to detect the chromosome 7q11.23 deletion. METHODS: Twenty-four suspected WBS cases were recruited following ethical clearance and informed consent. Blood was obtained, DNA extracted and spectrophotometrically quantified using standard methods. To detect the deletion by dosage analysis, a target region within a gene located in the WBS commonly deleted region of 7q11.23 was amplified together with a control region in a duplex sqPCR assay. The control region was telomeric to the WBS commonly deleted region and was located in chromosome 7q31.2. The two target regions within the deleted region namely a locus within ELN and a marker in the intergenic region between FZD9 and FKBP6 and designated IFF, were amplified in separate duplex sqPCR assays. The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene was used as the control for normalization. Included in the assay were a non-deleted and deleted individuals' samples. RESULTS: Nineteen patients were identified to have the deletion while five did not. All 24 patients' results were confirmed by whole exome sequencing and 11 also by fluorescence in-situ hybridization (FISH). CONCLUSIONS: The data obtained indicates the sqPCR assay developed in this study to be an accurate and reliable diagnostic test for WBS. Most Sri Lankan patients with WBS are diagnosed clinically, as many parents of affected WBS children are unable to afford currently available molecular diagnostic testing. This low cost sqPCR test is therefore likely to benefit Sri Lankan WBS patients, by enabling genetic testing for confirming or refuting a clinical diagnosis of WBS and may be of use in other low and middle income countries.Item Survey on the psychosocial impact of COVID-19 on the Sri Lankan mental healthcare system and the needs of frontline healthcare workers in the post-covid era(Sri Lanka Medical Association, 2023) Wijesinghe, C.; Chandradasa, M.; Ranwella, P.; Samaranayake, A.; Wickrama, P.; Gamage, N.; Siriwardane, G.; Goonathilake, N.; Perera, S.; Dahanayake, D.; Mendis, J.; Kapila, R.INTRODUCTION: The COVID-19 pandemic severely strained the health care in Sri Lanka. The subsequent economic crisis compounded this issue. Priority was given to treating those afflicted with COVID-19 and preventing its spread, and healthcare staff faced immense difficulties dealing with the situation. The psychosocial impact of COVID on health care staff has not been properly assessed or addressed. OBJECTIVES: A study was conducted to identify the psychosocial impact of COVID-19 among four different categories of health care workers, and perform a needs assessment among these groups. METHODS: A convenient sample of frontline health workers, mental health teams, 1926 mental health helpline workers and 1990 Suwa Sariya emergency ambulance service staff were assessed via a self-administered questionnaire for mental health impact, work capacities and needs. RESULTS: Among frontline workers (n=188), 42.5% experienced anxiety symptoms, 12.8% depressive symptoms and 4.1% suicidal thoughts. Most (58.9%) lacked a psychological support system at the workplace. Only 20% have accessed specific programs or services at their workplace to obtain support for mental health issues, and all have benefitted from them. All categories of health workers lacked training and resources. CONCLUSION: The findings demonstrate that a significant amount of health care workers undergo psychological problems in the course of their work especially in the aftermath of the COVID-19 pandemic. The analysis reveals that Sri Lanka lacks structured psychological support systems for health workers and needs more resources and training. Psychological support for health workers through strengthening resources and training should be prioritised when planning service development.Item Chracterisation of beta giobin mutations in Sri Lankan patients with betathalassaemia intermedia(Sri Lanka Medical Association, 2013) Perera, S.; Silva, D.P.S.I.; Hapugoda, M.; Wickramarathne, M.N.; Wijesirwardhena, I.; Efremove, D.G.; Fisher, C.A.; Weatherall, D.J.; Premawardhena, A.P.INTRODUCTION AND OBJECTIVES: Patients with beta thalassaemia intermedia account for a third of patients attending thalassaemia clinics in Sri Lanka. They show immense phenotypic diversity, the genetic basis for which has not been identified so far. Objective were to characterise beta globin gene mutations in Sri Lankan thalassaemia intermedia patients and to determine how it to influences disease severity. METHODS: We identified 64 thalassaemia intermedia patients from the five main thalassaemia centers; Anuradhapura (n= 6), Kuruncgala (n= 4), Ragama (n= 42), Badulla (n=7) and Chilaw (n=5). Their beta globin DNA sequences were analyzed using ABI PRISM 313lx genetic analyser. RESULTS: Of sixteen patients identified to be homozygous for beta mutations, eleven carried mild beta alleles, IVSI 5 G_C (n= 10) and a rare homozygous promoter mutation - 90 C_T (N=l). Other five were shown to have different types of severe iputations in homozygous state. Nearly half the sample (n=39) was heterozygous for beta mutations. Of them 33 showed mild to severe mutation in one of the alleles IVSI-5 G_C (n=12), IVSI-1 G_A (n= 11) were the commonest. Two patients who were hetcrozygones for beta mutation had a highly unstable Hb variant haemoglobin Mizuho causing severe haemolytic anacma. Hb variants Hb G-Szuhu and Hb G-Coushatta were identified in two patients. CONCLUSIONS: We identified types of beta mutations in some patients with thalassaemia intermedia, which account for the clinical severity.Item Oxidative stress and antioxidant deficiency in the β-thalassaemia in Sri Lanka(Sri Lanka Medical Association, 2021) Perera, S.; Allen, A.; Mettananda, S.; Rodrigo, R.; Perera, L.; Darshana, T.; Moggach, F.; Jackson-Crawford, A.; Heirene, L.; Fisher, C.; Olivieri, N.; Rees, D.; Allen, S.; Premawardhena, A.Introduction In the β thalassaemias oxidative stress is potentially high and this could be further exacerbated in the absence of robust antioxidant defences, such as nutritional vitamin C and E deficiencies. We undertook a comprehensive assessment of oxidant, antioxidant and inflammatory status in patients with subtypes of β-thalassaemia to study these factors in detail. Methods Consenting patients attending the thalassaemia centre in Ragama, (between November 2017 and June 2018) were assessed for the following: methaemoglobin, plasma haemoglobin, heme and ferritin as sources of oxidants, plasma haptoglobin, hemopexin and vitamins C and E as markers of antioxidants, plasma interleukin-6 and C-reactive protein for inflammation. Fruit and vegetable intake was determined by dietary recall. Results 162 patients were recruited. (59 HbE β-thalassaemia, 50 β-thalassaemia major, 40 β-thalassaemia intermedia, 13 HbS β-thalassaemia. Median age was 26.0 years (IQR 15.3-38.8), 101 (62.3%) were female. Oxidants were frequently increased and antioxidants depleted with high levels of oxidant damage, hypoxia and inflammation. Abnormalities were most severe in HbE-β thalassaemia and least severe in β thalassaemia intermedia. Oxidative stress was also more severe in splenectomised patients. Plasma vitamin C concentration was below the lower level of quantitation in 86/160 (53.8%) patients and vitamin E in 130/160 (81.3%) patients. Less than 15% of patients ate fresh fruits or raw vegetables frequently. Conclusion Markedly increased oxidative stress and antioxidant deficiency were observed in this study group, especially in those with HbE β-thalassaemia. Vitamin C & E supplementation may have a role in the long-term management of thalassaemia syndromes.Item Pitfalls in the diagnosis of β-Thalassemia Intermedia(Informa Healthcare, 2021) Perera, S.; Allen, A.; Rees, DC.; Premawardhena, A.We present case histories of three patients who had β-thalassemia (β-thal) trait with 'unusual severity' managed as β-thal intermedia (β-TI) where the basis of disease severity could not be explained with routine hematological and genetic investigations. The clinical diagnosis of 'thalassemia intermedia' was justifiable as they had a β-thal mutation and disease severity that did not fit in with either β-thal trait or with β-thal major (β-TM). As mutations of α, β, and γ genes could not explain the unusual severity of the disease, further analysis with next-generation sequencing (NGS) for red cell diseases was carried out, which led to the diagnosis of coexisting membranopathies. This case series highlights the inherent difficulty in the diagnosis of β-TI with certainty in some patients where the genetic basis is not clear-cut.Item Psychological wellbeing and mental health amongst medical undergraduates: A descriptive study assessing more than 1,000 medical students in Sri Lanka(London Avenue Publishing Co, 2022) Dahanayake, D.; Rajapakse, H.; Wickramasinghe, A.; Chandradasa, M.; Rohanachandra, Y.; Perera, S.; Nillo, A.M.; Molodynski, A.BACKGROUND: Studies from around the world have shown higher rates of anxiety, depression, alcohol and other drug use, and burnout in medical students. AIMS: The aim of this study was to identify the socio-demographic factors and severity of difficulties Sri Lankan medical students face regarding psychological wellbeing and burnout. METHOD: This one-off survey used a cross-sectional design, assessing substance use, psychological wellbeing, and burnout using the CAGE, GHQ-12, and OLBI. The survey was open to all medical students in six universities in Sri Lanka. Chi-square analysis was used to assess the statistical significance related to categorical dependent variables and one-way ANOVA for continuous dependent variables. RESULTS: A higher prevalence of diagnosed mental health conditions was found following admission to the medical course in comparison prior to admission. Sixty-two percent of students had a score of more than 2 on the GHQ-12 indicating caseness. The OLBI identified exhaustion in 79% of students. The CAGE questionnaire was positive in 4.8% of students. CONCLUSIONS: Only a small proportion of students are recognizing their mental health difficulties and seeking help. Further understanding is required as to why this is, as well as re-evaluation of the demands of the curriculum. Effective ways of regularly identifying and providing practical and evidence-based support for mental health problems in medical and other undergraduates need to be identified and introduced. KEYWORDS: Sri Lanka; Wellbeing; burnout; medical students.Item Marriage patterns in Sri Lanka and the role of consanguinity in thalassaemia: A cross sectional descriptive analysis(Sri Lanka Medical Association, 2019) Goonatilleke, M.D.D.C.; de Silva, S.T.; Rodrigo, R.; Perera, S.; Goonathilaka, G.W.M.R.G.B.; Ramees, L.; Mettananda, S.; Weatherall, D.L.; Premawardhena, A.P.INTRODUCTION & OBJECTIVES: Consanguineous marriages play an important role in the propagation of thalassaemia. There is a paucity of data on consanguineous marriages in modern Sri Lankan society and its effect on thalassaemia births. We studied sociological aspects of Sri Lankan marriages with emphasis on consanguinity, and the prevalence of consanguinity in the parents of patients with thalassaemia. METHODS: Three marriage registrars from each district were asked to record details about the partners of all marriages they registered for 6 months, from July 2009. Parents of patients with thalassemia were interviewed separately, to identify any consanguinity. RESULTS: A total of 5249 marriages were recorded from 22 districts. Average age at marriage was 27.2 9 years for males and 24.0 8 years for females. 3737/5249 (71.2%) of all marriages were Love Marriages, except in the Moor community where 89.2% were Arranged Marriages. Female literacy and education tier levels were higher than in males. Overall national consanguinity rate was 6.4% (337/5249). It was highest among Tamils (20.4%), but only 3.3% among Sinhalese and 3.1% among Moors. In the parents of 405 patients with thalassaemia, overall consanguinity rate was 11.1% (45/405): it was highest among Tamils (33.3%) and lowest among Sinhalese (9.4%). CONCLUSION: Consanguinity among patients with Thalassaemia was almost double the national average. Though not the dominant cause, more emphasis should be given to consanguinity when conducting thalassaemia prevention campaigns. Since they are older and better educated at marriage, female partners should be better targeted in such health education campaigns.Item Transfusion-transmitted Hepatitis C: A cluster of cases in transfusion-dependent Thalassaemia patients in Sri Lanka(Blackwell Scientific Publications,, 2020) Perera, S.; Bonsall, D.; Niriella, M.A.; Allen, A.; Peries, A.C.; Nelumdeniya, U.B.; Dissanayake, R.; Silva, I.; de Cesare, M.; Klenerman, P.; Weatherall, D.J.; Roberts, D. J.; Premawardhena, A.P.OBJECTIVES: To report the clinical and virologic epidemiology of a recent epidemic of hepatitis C in thalassaemia patients in Sri Lanka. BACKGROUND: Transfusion-dependent thalassaemia patients remain at risk for hepatitis C virus (HCV). Here, we report a cluster of recent HCV infections in Sri Lankan thalassaemia patients and examine the phylogenetic relationship of viral sequences. METHODS: We conducted two prospective cross-sectional surveys of 513 patients in four Sri Lankan thalassaemia centres in 2014/2015 and re-surveyed one centre in 2016. We screened for anti-HCV antibodies using the CTK Biotech enzyme-linked immunosorbent assay (ELISA) kits and confirmed active infection by reverse transcription-polymerase chain reaction (RT-PCR) for HCV-RNA. HCV genomes were sequenced by unbiased target enrichment. RESULTS: Anti-HCV antibodies were found in 116/513 (22.6%) of patients initially tested. Active hepatitis C infection was found in 26 patients with no cases of active hepatitis B infection. Of 26 patients with HCV, two were infected with genotype 1(a), and the rest had 3(a). In a single centre (Ragama), 122 patients (120 new cases and two previously tested, but negative) were retested for anti-HCV antibodies. 32/122 (26.2%) patients were seropositive. Twenty-three (23/122; 18.8%) of these new cases were confirmed by HCV PCR (all genotype 3[a]). CONCLUSIONS: There is a significant cluster of recent HCV cases in multiply transfused thalassaemia patients in several centres in Sri Lanka. Most of the viruses shared a close phylogenetic relationship. The results are consistent with recent continuing transfusion-transmitted HCV infection. Routine surveillance for HCV of chronically transfused patients is required irrespective of screening of blood products.Item Molecular diagnosis of velo-cardio-facial syndrome among sri lankan patients with congenital cardiac defects(Sri Lanka College of Paediatricians, 2015) Tevarajan, I.; Ranaweera, D. M.; Perera, S.; Samarasinghe, D.; Morawakkorala, R.; Silva, R. L.; de Silva, D.; Chandrasekharan, N.V.Velo cardio facial Syndrome (VCFS) is caused by a 3 Mb deletion of chromosome 22qll.2. Its multiple clinical features include orofacial clefting, congenital cardiac defects (especially conotruncal),developmental delay and learning difficulties. Hypoparathyroidism and thymic hypoplasia are associated. Dysmorphic features include expressionless face, prominent nose, narrow eyes and long fingers/ toes. Clinical diagnosis is difficult due to its variability making molecular diagnosis essential but this is often too expensive for widespread use. We have developed a less expensive semi-quantitative PCR method for diagnosing VCFS and report preliminary results in congenital cardiac defect patients.OBJECTIVE: • Identify the 22qll.2 deletion syndrome among a selected group of children with typical cardiac defects • Describe clinical features of affected cases DESIGN, SETTING AND METHOD: TweIve children (6 males, mean age 3y lmo) with conotruncal congenital cardiac anomalies or cardiac defects associated with other clinical feature of VCFS were .recruited following informed consent from parents. Ethical approval had been granted for this study. A blood sample was obtained for DNA extraction and the clinical data recorded. Molecular diagnosis was performed using semi-quantitative PCR. RESULTS: Three cases were positive for the deletion. Their cardiac anomalies were an interrupted aortic arch,tetralogy of Fallot and right sided aortic arch. None had palatal anomalies and two (67%) had learning difficulties. None had a positive family history. Only one had facies that were typical. The negative cases included six with aortic arch anomalies, none with clefting and 4 with learning difficulties(44). Two had a family history suggestive of VCFS and two had typical facial features. CONCLUSIONS: Three out of the 12 children were positive for the 22qll.2 deletion.Item Clinical and molecular heterogeneity of β thalassaemia intermedia in Sri Lanka(Faculty of Medicine, University of Kelaniya, Sri Lanka, 2016) Perera, S.A third of all patients attending thalassaemia centres in Sri Lanka have non-transfusion dependent thalassaemia (NTDT). The majority of these have Hb E β-thalassaemia. The genetic basis of non-E β-thalassaemia intermedia (TI) was studied in an attempt to correlate their genotype with the phenotype. Fifty unrelated TI patients were identified from the main thalassaemia centres, assessed clinically and categorized into ‘mild’, ‘moderate’ and ‘severe’ groups. DNA analyses were performed using standard techniques. Seventeen patients were homozygous or compound heterozygous for β mutations. Five of the homozygotes who carried two mild β alleles had mild disease. Nine inherited two severe β alleles with either one or two α gene deletions; despite the α deletions, they had severe disease. Thirty three patients were heterozygous for a β mutation: IVSI-5 G>C was the commonest. Twenty eight of the heterozygotes carried excess α genes and had a mild-moderate phenotype. The clinical outcomes of this TI population were mostly explained by the genotypes linked to the α and β gene cluster. However, in a minority, the existence of other causative genetic determinants remains to be defined.