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S Fucharoen

Publications and source records attributed to S Fucharoen.

At least 145 records · Page 8Linked to original sources
PubMed1990

Molecular basis of HbE-beta-thalassemia and the origin of HbE in northeast Thailand: identification of one novel mutation using amplified DNA from buffy coat specimens.

Amplification of DNA via polymerase chain reaction directly from a small amount of a buffy coat fraction was used to study the molecular basis of HbE-beta-thalassemia in the northeastern Thai population. Eight different mutations including the new one causing a beta o-thalassemia phenotype were detected. This novel mutation is an amber mutation at codon 26, which occurs at the same position as that of HbE; the most common hemoglobin variant in Southeast Asian countries. A pitfall in detection of the HbE mutation by restriction enzyme analysis was pointed out and differential diagnosis of the HbE mutation and the novel one by using allele specific oligonucleotide probes were described. Analysis of polymorphic restriction sites in the beta-globin gene cluster containing the beta E gene revealed two previously undescribed haplotypes in the Southeast Asian populations, which provide evidence for the multiple origins of beta E gene in Southeast Asian populations.

Alleles↗
PubMed1990

Hemoglobin Dhonburi alpha 2 beta 2 126 (H4) Val----Gly: a new unstable beta variant producing a beta-thalassemia intermedia phenotype in association with beta zero-thalassemia.

While investigating the mechanism of a beta-thalassemia intermedia phenotype in a 34 year old Thai male, a new Hb variant beta 126 Val----Gly named Hb Dhonburi was discovered. Genetic and structural studies revealed the existence of a beta zero-thalassemia genotype in association with the beta variant. The new variant is unstable but exhibits normal oxygen binding properties. Hb Dhonburi was also discovered in the mother of the propositus in association with Hb E.

1-Propanol↗
PubMed1990

Molecular heterogeneity of beta-thalassaemia in the Japanese: identification of two novel mutations.

Five unrelated Japanese beta-thalassaemia genes, from one homozygote and four heterozygotes, have been systematically characterized using DNA polymorphism analysis, polymerase chain reaction, dot-blot hybridization and direct sequencing of amplified genomic DNA. Four different molecular defects were observed on three different beta-globin gene frameworks. One of these, the A----G mutation in the TATA box, a previously described mutation, was detected by dot-blot hybridization in one homozygote and one heterozygote with the beta-globin gene of framework 2. The second mutation is a C----T substitution at position 654 of IVS-2, the mutation commonly found in Chinese, which was associated with the framework 1 gene. Another two mutations, both associated with framework 3 genes, are novel ones; an amber mutation in codon 90 (GAG to TAG) and a frameshift (+G) insertion in codon 54, both of which cause a beta 0-thalassaemia phenotype by premature termination of the beta-globin chain synthesis.

Adult↗
PubMed1990

A single nucleotide deletion in codon 123 of the beta-globin gene causes an inclusion body beta-thalassaemia trait: a novel elongated globin chain beta Makabe.

The beta-globin gene from a Japanese individual with an inclusion body beta-thalassaemia trait has been characterized by gene cloning and DNA sequencing. An adenine deletion was detected at the first position of codon 123 (ACCCC) of one allele whereas the other allele had a normal sequence. Heterozygosity for this mutation in the patient was confirmed by Southern blots of the genomic DNA digested with HphI, the recognition site of which is eliminated by this deletion. This one base deletion results in the shift of a reading frame in such a manner that the normal termination codon is out of phase. This frameshift mutation results in the synthesis of an elongated beta-globin chain with 10 extra amino acid residues and with an altered C-terminus. Analysis of labelled globin chains using CM-cellulose column chromatography failed to demonstrate any abnormal protein, thereby suggesting that the beta-globin chain variant is highly unstable and probably degrades rapidly after synthesis. This event will lead to an accumulation of free alpha-chains precipitating in the red blood cells and an inclusion body beta-thalassaemia phenotype would ensue.

Amino Acid Sequence↗
PubMed1990

Molecular characterization and nonradioactive detection of beta-thalassemia in Malaysia.

The spectrum of beta-thalassemia mutations in Malaysia has been determined in 45 beta-thalassemia chromosomes using dot blot hybridization of the polymerase chain reaction amplified DNA and direct DNA sequencing. Eleven different molecular defects, including those previously detected in Chinese, Asian Indians, and American blacks, and a novel frameshift mutation causing beta zero-thalassemia were detected. Since this novel mutation, a T deletion in codon 15 creates a new restriction site for EcoRII enzyme; the mutation could be detected by EcoRII digestion of the appropriate amplified fragment. The results of the present study provide additional information on the molecular heterogeneity of beta-thalassemia in this population. We also demonstrated the nonradioactive detection method of the beta-thalassemia mutation based upon the digoxigenin-labeled oligonucleotide probes.

Base Sequence↗
PubMed1990

Thai G gamma (A gamma delta beta)zero-thalassemia and its interaction with a single gamma-globin gene on a chromosome carrying beta zero-thalassemia.

Clinical manifestations and hematologic data of thalassemia intermedia were observed in three siblings of a Thai family. Analyses of the hemoglobin of their parents and other siblings indicated that they inherited a delta beta-thalassemia gene from the father and a beta zero thalassemia gene from the mother. Globin gene mapping confirmed that they carry two abnormal beta-globin gene complexes. On one chromosome more than 70 kb of DNA was removed which resulted in G gamma (A gamma delta beta)zero-thalassemia. The deletion started at the Hind III site located just 3' to the G gamma gene, and extended downstream to a region recognized by the p3'N 2.8R probe which is located more than 45 kb from the 3' end of the beta gene. The other chromosome carried a beta zero thalassemia gene, and a 5 kb deletion between the G gamma and A gamma genes which produced a hybrid -GA gamma- gene. A synthetic oligonucleotide probe showed that this beta zero thalassemia arose from a C----T mutation at position 654 of IVS-II in the beta-globin gene.

Adolescent↗
PubMed1990

Cardiac involvement in beta-thalassemia/hemoglobin E disease: clinical and hemodynamic findings.

Clinical and hemodynamic studies were conducted in 6 women and 2 men with beta-thalassemia/hemoglobin E disease. All except one had splenectomy. The patients were hospitalized in the state of congestive heart failure. The systemic blood pressure was low or normal. The electrocardiograms revealed normal sinus rhythm in all, right axis deviation in some, right atrial enlargement in the majority and repolarization abnormalities in some. The echocardiograms were sensitive to detect the right heart abnormalities and pericardial effusion. Cardiac catheterization disclosed moderate to marked hypoxemia. All patients except one had pulmonary hypertension. Some had left ventricular dysfunction. From this study. It is concluded that right heart involvement secondary to diffuse pulmonary thromboembolic disease is a major complication of beta-thalassemia/hemoglobin E disease.

Adolescent↗
PubMed1990

The molecular basis of beta-thalassemia in Thailand: application to prenatal diagnosis.

To enable the prenatal diagnosis of beta-thalassemia by direct detection of the mutant beta-globin genes, we have determined the spectrum of mutations causing this disease in Thailand. The techniques employed included a combination of synthetic oligonucleotide probe hybridization, direct sequencing of genomic DNA enzymatically amplified by the polymerase chain reaction, and cloning and sequencing of the beta-globin genes. A total of 116 beta-thalassemia genes from 78 Hb E/beta-thalassemia patients and from 19 homozygous beta-thalassemia patients were analyzed, and the mutation was characterized in 112/116 (97%) of them. Eleven mutations were found, of which four (-CTTT in codon 41/42, AAG----TAG in codon 17, C----T in position 654 of the IVS-2 region, and A----G in position -28 upstream of the beta-globin gene) accounted for 83%; two previously undescribed mutations have been identified. The spectrum of beta-thalassemia mutations is similar to that reported among the Chinese. However, within the Thai population itself, patients with homozygous beta-thalassemia show a wider spread of mutations in comparison with the Hb E/beta-thalassemia group, in whom the frameshift 41/42 mutation predominates at a frequency of 62%. This difference in distribution may reflect the difference in ethnic origin of the two groups. Characterization of these mutations should aid the planning of a prenatal diagnosis program for beta-thalassemia in Thailand.

Base Sequence↗
PubMed1989

Molecular basis of beta (0)-thalassemia/HbE disease in Thailand.

The molecular basis of beta(0)-thalassemia/HbE disease in 30 Thai patients was investigated using DNA amplification and dot-blot hybridization with a number of allele specific oligonucleotide probes. The mutations identified were 17 cases of 4 base-pair deletion at codons 41-42, 4 cases of amber mutation at codon 17, and one case each of an ochre mutation at codon 35, a single base substitution at position 5 of IVS-1, and a single base substitution at position 654 of IVS-2.

Autoradiography↗
PubMed1989

A novel ochre mutation in the beta-thalassemia gene of a Thai. Identification by direct cloning of the entire beta-globin gene amplified using polymerase chain reactions.

The beta-globin genes from a Thai patient compound heterozygous for beta-thalassemia and HbE disease were investigated. The 3.0-kilobase fragment containing the entire beta-globin gene was amplified by polymerase chain reaction, using Taq DNA polymerase followed by direct cloning of the amplified product into plasmid DNA. Sequence analysis of the thalassemia gene revealed only one base change, a C-A transversion within codon for an amino acid 35. This new mutation creates a premature terminator, TAA, an ochre codon, and results in a beta 0-thalassemia phenotype. The same result was obtained when this mutation was analyzed using a conventional cloning technique, direct sequencing of the amplified product, and hybridization with allele-specific oligonucleotide probes. No misincorporation was detected in the sequence analysis of the 3.0-kilobase insert of five clones of the amplified products obtained from genomic DNA of a normal individual. This approach is a rapid and accurate method for molecular cloning of the beta-globin gene and also other genes, the partial nucleotide sequences of which are known.

Base Sequence↗
PubMed1989

Selective enzymatic amplification of alpha 2-globin DNA for detection of the hemoglobin Constant Spring mutation.

Hemoglobin Constant Spring is an elongation mutation of the alpha 2-globin locus that results in a thalassemic phenotype. It has a high prevalence in Asian populations. When inherited with other alpha-thalassemia determinants, the Constant Spring gene has the potential to cause severe forms of alpha-thalassemia. Accurate diagnosis of the condition with standard hemoglobin electrophoresis is unreliable due to the small to undetectable amounts of the mutant hemoglobin present. Because of the extensive sequence homology of the alpha 1 and alpha 2 loci, allele-specific hybridization to total genomic DNA containing the Constant Spring gene would not distinguish between heterozygous and homozygous hemoglobin Constant Spring. Selective enzymatic amplification of alpha 2-globin DNA sequences, however, allows unambiguous diagnoses to be made using allele-specific hybridization. This method is useful for providing accurate genetic counseling and prenatal diagnosis in populations and specific families in which precise diagnosis is important.

Adult↗
PubMed1989

Molecular basis of beta-thalassemia in Thailand: analysis of beta-thalassemia mutations using the polymerase chain reaction.

beta-Thalassemia mutations in 71 chromosomes of Thai patients from the northeast, the middle and the south of the country were investigated using dot blot hybridization of PCR (polymerase chain reaction)-amplified DNA with allele-specific oligonucleotide probes. Eight different known molecular defects were detected, at different frequencies. There was an amber mutation in codon 17, a C-T transversion at position 654 of IVS-2, a frameshift mutation between codons 71 and 72, an A-G transition at nucleotide -28 within the TATA box (known as Chinese mutations), a G-T transversion at position 1 of IVS-1 (an Indian mutation), a 4 bp deletion in codons 41/42 and a G-C transversion at position 5 of IVS-1 (described as both Chinese and Indian mutations) and a Thai original mutation, an ochre mutation in codon 35. Analysis of the three unknown alleles by DNA sequencing of the cloned DNA fragment amplified by PCR revealed an A-G substitution at the second position of the codon for amino acid 19 (AAC-AGC). The analytic approach used in the present study and the characteristic distribution of mutations in each region of Thailand will prove useful for setting up a prenatal diagnosis program.

Alleles↗
PubMed1989

Detection of beta-thalassemia and hemoglobin E genes in Thai by a DNA amplification technique.

Enzymatic DNA amplification and polyacrylamide gel electrophoresis, which demonstrate different sizes of DNA fragments, were used to detect the common mutations causing beta-thalassemia and hemoglobin (Hb) E in Thai people. The 4-bp deletion at codons 41 and 42 can be detected directly by polyacrylamide gel electrophoresis and ethidium bromide staining. Whereas the nonsense mutations at codon 17 (AAG----TAG) and Hb E (GAG----AAG at codon 26) were detected after digestion of the amplified DNA with the enzymes MaeI and MnlI, respectively.

Codon↗
PubMed1989

Effects of thalassaemic serum on the in vitro development of the malarial parasite Plasmodium falciparum.

Sera from thalassaemic individuals were experimentally tested for their suppressive effects on the in vitro development of asexual stages of Plasmodium falciparum. Cultures in sera collected from six patients who had classical haemoglobin H disease (alpha-thal1-alpha-thal2) and six patients who had haemoglobin H disease with haemoglobin (Hb) Constant Spring (alpha-thal1-CS) showed a significantly higher degree of inhibition of parasite multiplication than cultures of thalassaemic erythrocytes in sera from healthy individuals. Similarly, sera from 12 patients with beta-thalassaemia/haemoglobin E (beta-thal-HbE) diminished parasite development in vitro. Schizonts of P. falciparum cultured in erythrocytes from non-thalassaemic individuals containing normal Hb (alpha 2 beta 2) were also inhibited when thalassaemic serum was used in place of normal serum. The degree of inhibition was proportional to the concentration (vol/vol) of the thalassaemic serum.

Adult↗