Conference Papers
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/6561
This collection contains abstracts of conference papers, presented at local and international conferences by the staff of the Faculty of Medicine
Browse
5 results
Search Results
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 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 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 Molecular diagnosis of Williams Buren syndrome in a cohort of Sri Lankan patients(Sri Lanka Medical Association, 2012) Ranaweera, D.M.; de Silva, D.; Samarasinghe, D.; Perera, S.; Rajapaksha, N.; Chandrasekharan, N.V.INTRODUCTION: Williams Bueren Syndrome (WBS) is a common genetic cause of congenital heart defects associated with developmental delay, hypercalcaemia and characteristic facial dysmorphism. It is caused by a 1.5 to 1.8 Mb deletion of chromosome 7qll.23 involving the loss of around 23 genes including the elastin (ELN) gene. This study reports the development of a semi quantitative PCR method to diagnose WBS. AIMS: To establish a molecular diagnostic test for WBS and determine the frequency of ELN deletions among clinically suspected cases. METHODS: Sixteen suspected WBS cases identified by two paediatric cardiologists were recruited following ethical clearance and informed consent. DNA was extracted and dosage analysis was carried out using semi-quantitative PCR. In a multiplex PCR reaction normal (N), positive control (with a confirmed deletion) and patients' (PJ DNA was amplified using 2 primer pairs which amplified regions within the ELN gene and the CFTR gene on chromosome 7 but outside the deleted region. Following agarose gel electrophoresis, the amplified products were quantified. A ratio of P:N of 0.5 indicated the presence of a deletion while a ratio of 1 indicated the absence of a deletion. RESULTS: Among sixteen suspected cases, 12 (75%) had an ELN gene deletion while 4 cases did not. CONCLUSIONS: This semi-quantitative PCR method was able to distinguish ELN deleted cases from the non deleted ones. The preliminary data supports this as a useful diagnostic test for WBS but validation is required before its clinical use.