Autosomal dominant hereditary ataxia in Sri Lanka

Background Spinocerebellar ataxias (SCA) are a group of hereditary neurodegenerative disorders. Prevalence of SCA subtypes differ worldwide. Autosomal dominant ataxias are the commonest types of inherited ataxias seen in Sri Lanka. The aim of the study is to determine the genetic etiology of patients with autosomal dominant ataxia in Sri Lanka and to describe the clinical features of each genetic subtype. Methods Thirty four patients with autosomal dominant ataxia were recruited. For every patient the following was done: recording of clinical details and genotyping for SCA 1, 2, 3, 6, 7, 8, 12, and 17. Results Sixty one per cent of the subjects were identified as SCA1. One subject had SCA2, 12 remain unidentified. Mean age at onset was 34.8 ± 10years for SCA1 and 32.7 ± 9.8 for non SCA1. 76% of SCA1 patients and 50% of non SCA1 were using walking aids. Quantification of symptoms and signs were similar in the SCA1 and non SCA1 groups. Clinical depression was evidenced in 68.4% of SCA1 and 75% non SCA-1 patients. Mean CAG repeat length in SCA1 patients was 52.0 ± 3.8, with greater anticipation seen with paternal inheritance. Conclusion SCA1 was the predominant subtype and showed similar phenotype to previous reports. However, disease severity was higher and depression more prevalent in this population than previously described

Leading Article Cytogenetic testing in paediatrics: Some aspects of the Sri Lankan scenario

Cytogenetic testing or chromosome culture and karyotyping was introduced to Sri Lanka in October 1983 with the establishment of the Human Genetics Unit of the Faculty of Medicine, University of Colombo. In 2006 a private sector laboratory too, entered the field. There has been an upward trend in the number of cytogenetic tests performed in Sri Lanka since 1983 (Figure 1). At the same time an unknown number of samples are sent abroad for testing. Figure 2 Karyogram of the baby at 450 band banding level showing an unbalanced translocation between chromosome no.14 and chromosome no.21. The karyotype is 46, XY, t (14; 21)

The low frequency of Y chromosome microdeletions in subfertile males in a Sinhalese population of Sri Lanka

Aims: This study was designed to determine the prevalence of azoospermia factor (AZF) microdeletions on the Y chromosome in Sri Lankan Sinhalese infertile men with azoospermia and severe oligozoospermia. Settings and Design: The patient group was 207 karyotypically normal infertile Sinhalese males. Materials and Methods: The presence of 13 sequence-tagged site (STS) markers in the AZF region was tested using multiplex polymerase chain reaction (M-PCR). One hundred and twenty unselected men were also studied as a control group. Results: Three (1.5%) had classic Y chromosome microdeletions in the AZFc sub-region. Conclusions: These results suggest a much lower Y chromosome microdeletion frequency than previously thought, even among a strictly selected group of sub-fertile males in Sri Lanka

Frequency of Hereditary Hemochromatosis Gene (HFE) Variants in Sri Lankan Transfusion-Dependent Beta-Thalassemia Patients and Their Association With the Serum Ferritin Level

IntroductionCo-inheritance of hereditary hemochromatosis (HFE) gene variants p. C282Y and p.H63D worsen iron overload in transfusion-dependent thalassemia. Data on the HFE gene variants in Sri Lankan patients with thalassemia have not been extensively studied. This study aimed to analyze the p.C282Y and p.H63D variants in transfusion-dependent beta (β) and HbE/β-thalassemia patients and establish an association between these variants and their serum ferritin levels.Materials and MethodsA total of 125 transfusion-dependent β-thalassemia major and HbE/β thalassemia patients were tested for the c.845G&amp;gt;A (p.C282Y) and c.187C&amp;gt;G (p.H63D) HFE gene variants using the multiplex Amplification Refractory Mutation System Polymerase Chain Reaction method. For phenotype-genotype correlation, serum ferritin levels, the erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels were measured. The standard descriptive statistics were used for data analysis.ResultsThe study cohort consisted of transfusion-dependent 123 β-thalassemia and 2 HbE/β-thalassemia patients. The p.C282Y variant was not detected in any patient; allele frequency for the wild type (c.845GG) was 100%. Twenty-three patients were heterozygous for the p.H63D variant allele, and the allele frequencies were c.187CC 91.8%, c.187CG 9.2%, and c.187GG 0%. The mean serum ferritin level was relatively higher (mean level 4,987 ng/ml) in the p.H63D heterozygous (c.187CG) group compared to the wild type (c.187CC) group (mean level 4,571 ng/ml), but the difference was statistically not significant (p = 0.865). Among the total study population, CRP, ESR, and serum glutamine aspartate transaminase (SGPT) were elevated in 9 (7.2%), 65 (52%), and 82 (65.6%) patients, respectively. Among the p.H63D c.187CG group, elevated CRP, ESR, and SGPT were present in 5 (5%), 15 (12%), and 18 (14.4%) patients, respectively. The detected sample number was low to correlate with the confounding effect of inflammatory disorders and liver damage on the serum ferritin levels.ConclusionsThe HFE gene variant p.C282Y is unlikely to cause iron overload in the Asian β-thalassemia patients; the rarity of this variant in the study cohort replicates the findings of other South Asian population studies of this variant. The presence of the p.H63D variant could be a potential risk factor for iron overload in the β-thalassemia patients. A more extensive cohort study is required to validate this finding.</jats:sec

Adolescent Growth in Stature among Sinhalese Males: Preliminary Results of a Cross-Sectional Study

Cross-sectional stature growth profiles are presented for preadolescent, adolescent and young adult Sinhalese males of middle and upper socioeconomic status from Colombo, Sri Lanka. Sinhalese males are compared to cross-sectional standards for adolescent male stature developed by the National Center for Health Statistics (NCHS) of the U.S.A. While the shapes of the NCHS and Sinhalese cross-sectional growth curves are similar, the majority of Sinhalese adolescent males (\u3e 80%) fall below the N C H S 50th percentile for stature at a given age