11 research outputs found
Farmersâ Perceptions of and Adaptations to Climate Change in Southeast Asia: The Case Study from Thailand and Vietnam
The perceptions of climate change and adaptation choices made by farmers are important considerations in the design of adaptation strategies by policy makers and agricultural extension services. This paper seeks to determine these perceptions and choices by farmers in already poor environmental regions of Thailand and Vietnam especially vulnerable to climate change. Overall findings were that farmers do perceive climate change, but describe it in quite distinct ways and that location influences how farmers recognize climate change. Our 2007 and 2013 surveys show that farmers are adapting, but it is difficult to determine if specific practices are âclimate smartâ. Further, adaptation measures are informed by perception and, at least in the case of Vietnam, perceptions are shaped by the respondentâs characteristics, location variables and recent climate related shocks. Finally, the three climate variables of rainfall, temperature, and wind are the most important factors in explaining specific adaptation measures chosen by farmers. Farmer participation is an essential part of public actions designed to allow adaptation to climate change. Our research can also contribute to understanding farmer constraints and tailoring good overall strategies to the local heterogeneity of vulnerable locations
Molecular analysis of beta-globin gene mutations among Thai beta-thalassemia children: results from a single center study
Boonchai Boonyawat,1 Chalinee Monsereenusorn,2 Chanchai Traivaree2 1Division of Genetics, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand; 2Division of Hematology/Oncology, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand Background: Beta-thalassemia is one of the most common genetic disorders in Thailand. Clinical phenotype ranges from silent carrier to clinically manifested conditions including severe beta-thalassemia major and mild beta-thalassemia intermedia. Objective: This study aimed to characterize the spectrum of beta-globin gene mutations in pediatric patients who were followed-up in Phramongkutklao Hospital. Patients and methods: Eighty unrelated beta-thalassemia patients were enrolled in this study including 57 with beta-thalassemia/hemoglobin E, eight with homozygous beta-thalassemia, and 15 with heterozygous beta-thalassemia. Mutation analysis was performed by multiplex amplification refractory mutation system (M-ARMS), direct DNA sequencing of beta-globin gene, and gap polymerase chain reaction for 3.4 kb deletion detection, respectively. Results: A total of 13 different beta-thalassemia mutations were identified among 88 alleles. The most common mutation was codon 41/42 (-TCTT) (37.5%), followed by codon 17 (A>T) (26.1%), IVS-I-5 (G>C) (8%), IVS-II-654 (C>T) (6.8%), IVS-I-1 (G>T) (4.5%), and codon 71/72 (+A) (2.3%), and all these six common mutations (85.2%) were detected by M-ARMS. Six uncommon mutations (10.2%) were identified by DNA sequencing including 4.5% for codon 35 (C>A) and 1.1% initiation codon mutation (ATG>AGG), codon 15 (G>A), codon 19 (A>G), codon 27/28 (+C), and codon 123/124/125 (-ACCCCACC), respectively. The 3.4 kb deletion was detected at 4.5%. The most common genotype of beta-thalassemia major patients was codon 41/42 (-TCTT)/codon 26 (G>A) or betaE accounting for 40%. Conclusion: All of the beta-thalassemia alleles have been characterized by a combination of techniques including M-ARMS, DNA sequencing, and gap polymerase chain reaction for 3.4 kb deletion detection. Thirteen mutations account for 100% of the beta-thalassemia genes among the pediatric patients in our study. Keywords: mutation analysis, beta-globin gene, Thai childre
Clinical and molecular genetic features of Hb H and AE Bart’s diseases in central Thai children
Chanchai Traivaree,1,* Boonchai Boonyawat,2,* Chalinee Monsereenusorn,1 Piya Rujkijyanont,1 Apichat Photia1 1Division of Hematology/Oncology, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand; 2Division of Genetics, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand *These authors contributed equally to this work Background: α-Thalassemia, one of the major thalassemia types in Thailand, is caused by either deletion or non-deletional mutation of one or both α-globin genes. Inactivation of three α-globin genes causes hemoglobin H (Hb H) disease, and the combination of Hb H disease with heterozygous hemoglobin E (Hb E) results in AE Bart’s disease. Objective: This study aimed to characterize the clinical and hematological manifestations of 76 pediatric patients with Hb H and AE Bart’s diseases treated at Phramongkutklao Hospital, a tertiary care center for thalassemia patients in central Thailand.Patients and methods: Seventy-six unrelated pediatric patients, 58 patients with Hb H disease and 18 patients with AE Bart’s disease, were enrolled in this study. Their clinical presentations, transfusion requirement, laboratory findings, and mutation analysis were retrospectively reviewed and analyzed.Results: A total of 76 pediatric patients with Hb H and AE Bart’s diseases who mainly lived in central Thailand were included in this study. The clinical severities of patients with non-deletional mutations were more severe than those with deletional mutations. Eighty-six percent of patients with non-deletional AE Bart’s disease required more blood transfusion compared to 12.5% of patients with deletional AE Bart’s disease. Non-deletional AE Bart’s disease also had a history of urgent blood transfusion with the average of 6±0.9 times compared to 1±0.3 times in patients with deletional Hb H disease. The difference was statistically significant.Conclusion: This study revealed the differences in clinical spectrum between patients with Hb H disease and those with AE Bart’s disease in central Thailand. The differentiation of α-thalassemia is essential for appropriate management of patients. The molecular diagnosis is useful for diagnostic confirmation and genotype–phenotype correlation. Keywords: genotype, phenotype, Hb H disease, AE Bart’s disease, Thai childre
Genotype–phenotype correlation among beta-thalassemia and beta-thalassemia/HbE disease in Thai children: predictable clinical spectrum using genotypic analysis
Chanchai Traivaree,1 Chalinee Monsereenusorn,1 Piya Rujkijyanont,1 Warakorn Prasertsin,2 Boonchai Boonyawat3 1Division of Hematology/Oncology, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand; 2Department of Pediatrics, Queen Savang Vadhana Memorial Hospital, Chonburi, Thailand; 3Division of Genetics, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand Introduction: Beta-thalassemia is a group of inherited hemolytic anemias and one of the most common genetic disorders in Thailand. The clinical spectrum of beta-thalassemia disease ranges from mild to severe clinical symptoms including mild beta-thalassemia intermedia (TI) and severe beta-thalassemia major (TM). Objective: This study aimed to determine the correlation between beta-globin gene (HBB) mutations and their phenotypic manifestations by evaluating patients’ clinical characteristics, transfusion requirements, growth and hematologic parameters, and hemoglobin typing among pediatric patients treated at Phramongkutklao Hospital. Materials and methods: Seventy beta-thalassemia patients, including 63 with beta-thalassemia/hemoglobin E (HbE) and 7 with either homozygous or compound heterozygous beta-thalassemia, were enrolled in this study. Their clinical presentation, growth parameters and laboratory findings were reviewed and analyzed. The mean follow-up time was 10.52±5.62 years. Mutation analysis in each individual was performed using multiplex amplification refractory mutation system (M-ARMS), direct DNA sequencing of beta-globin gene and gap PCR for 3.4 kb deletion detection. Results: All 7 homozygous and compound heterozygous beta-thalassemia patients were classified in TM. Among 63 patients with beta-thalassemia/HbE, 58 were classified in TM and 4 were classified in TI. Mean age at diagnosis was 0.8±0.49 years for homozygous or compound heterozygous beta-thalassemia and 3.43±3.5 years for beta-thalassemia/HbE. The most common HBB mutation was HBB:c.126_129delCTTT [codon 41/42 (-TCTT)] found in 34 alleles (48.6%). The height for age was also lower in homozygous beta-thalassemia patients (<3rd percentile) compared to compound heterozygous beta-thalassemia patients (25–50th percentile). Conclusion: This study revealed a genotype–phenotype correlation of the most prevalent beta-thalassemia in Thai children using diagnostic capacity in genotypic analysis of HBB mutation. Our findings can provide a better prediction of clinical manifestation and severity by early identification of the type of the HBB mutations. Keywords: beta-thalassemia disease, hemoglobinopathy, mutation, clinical, childre
De novo MECP2 duplications in two females with intellectual disability and unfavorable complete skewed X-inactivation
Xq28 microduplications of MECP2 are a prominent cause of a severe syndromic form of intellectual disability (ID) in males. Females are usually unaffected through near to complete X-inactivation of the aberrant X chromosome (skewing). In rare cases, affected females have been described due to random X-inactivation. Here, we report on two female patients carrying de novo MECP2 microduplications on their fully active X chromosomes. Both patients present with ID and additional clinical features. Mono-allelic expression confirmed complete skewing of X-inactivation. Consequently, significantly enhanced MECP2 mRNA levels were observed. We hypothesize that the cause for the complete skewing is due to a more harmful mutation on the other X chromosome, thereby forcing the MECP2 duplication to become active. However, we could not unequivocally identify such a second mutation by array-CGH or exome sequencing. Our data underline that, like in males, increased MECP2 dosage in females can contribute to ID too, which should be taken into account in diagnostics