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Fulltext Prevalence of 3.7 and 4.2 deletions in Sudanese patients with red cells hypochromia and microcytosis

Osman HA, Hamid MMA, Ahmad RB, Saleem M, Abdallah SA

BMC Res Notes, 2020 Feb 10;13(1):65.
PMID: 32041645 DOI: 10.1186/s13104-020-4933-5

OBJECTIVE: Alpha-thalassemia is a genetic disorder characterized by deletions of one or more α globin genes that result in deficient of α globin chains reducing haemoglobin concentration. The study aimed to screen 97 patients with microcytosis and hypochromasia for the 3.7 and 4.2 alpha thalassemia deletion mutations.
RESULTS: Out of 97 patients screened, only 7 were carriers for the 3.7 deletion and all patients were negative for the 4.2 deletion. The 3.7 deletion was found in Foor, Hawsa and Rezagat Sudanese tribes. In the carriers of the 3.7 deletion, Red Blood Cells and Haematocrit were significantly increased. The Red Blood Cells were 7.23 ± 0.78 × 1012/L in adult males and 7.21 ± 0.67 × 1012/L in adult females while in children were 5.07 ± 0.87 × 1012/L. The mean cell volume and mean cell haemoglobin were significantly decreased, but the mean cell haemoglobin concentration slightly decreased. Haemoglobin levels didn't revealed statistically significant decrease in adult males (11.7 ± 0.57 g/dL) and adult females (11.25 ± 0.64 g/dL), while in children were (11.6 ± 2.95 g/dL). Haemoglobin electrophoresis revealed two patients of the 3.7 and 4.2 negative were carriers for β-thalassemia. The study concluded that α3.7 deletion has frequency of 0.07 in Sudanese with hypochromasia and microcytosis.

Matched MeSH terms: alpha-Thalassemia/diagnosis*; alpha-Thalassemia/genetics*; alpha-Thalassemia/epidemiology
Haemoglobin Constant Spring (HbA2: c.427T>C) and Haemoglobin Adana (HbA2: c.179G>A) in jaundiced Malaysian term neonates with clinically significant hyperbilirubinemia

Shwe S, Boo NY, Ong HK, Chee SC, Maslina M, Ling MMM, et al.

Malays J Pathol, 2020 Aug;42(2):253-257.
PMID: 32860378

INTRODUCTION: Haemoglobin Constant Spring (Hb CoSp) and Haemoglobin Adana (Hb Adana), are two non-deletion type of α-thalassemia reported in Malaysia. Owing to their structural instability, they cause hemolysis and hyperbilirubinemia. This observational study was part of a large study investigating multiple factors associated with severe neonatal jaundice. In this part we aimed to determine the prevalence of Hb CoSp and Hb Adana and their association with clinically significant neonatal hyperbilirubinemia (SigNH, total serum bilirubin (TSB>290µmol/L)) among jaundiced Malaysian term neonates.
MATERIALS AND METHODS: The inclusion criteria were normal term-gestation neonates admitted consecutively for phototherapy. PCR-restriction fragment length polymorphism method was applied on DNA extracted from dry blood spot specimens of each neonate to detect for Hb CoSp and Hb Adana gene. Positive samples were verified by gene sequencing.
RESULTS: Of the 1121 neonates recruited (719 SigNH and 402 no-SigNH), heterozygous Hb CoSp gene was detected in only two (0.27%) neonates. Both were SigNH neonates (0.3% or 2/719). No neonate had Hb Adana variant.
CONCLUSION: Hb CoSp was not common but could be a risk factor associated with SigNH. No Hb Adana was detected.

Matched MeSH terms: alpha-Thalassemia/diagnosis*
Fulltext An Unusual Association between Unilateral Intracranial Vessels Occlusion with Iron Deficiency Anaemia and Alpha-Thalassemia Trait: A Case Report

Lee YY, Bhaskar S

Case Rep Med, 2011;2011:271560.
PMID: 22229036 DOI: 10.1155/2011/271560

We report a 33-year-old Malay woman presented with acute left dense hemiparesis and an NIHSS score of 11/15. Computed tomography (CT) scan brain showed a massive right middle cerebral artery (MCA) territory infarct. The right internal carotid artery (ICA) and right proximal MCA were shown occluded from digital substraction angiography (DSA). Carotid dissection, carotid canal anomaly, and intercavernous communication were systematically ruled out. She had no risk factors for atherosclerosis. The connective tissue screening and thrombophilic markers were negative. However, she was anaemic on admission and subsequent investigations revealed that she had alpha-thalassemia and iron deficiency anaemia. The right ICA remained occluded from a repeat CT cerebral angiogram after one year, but otherwise she was neurologically stable. This case illustrates an unusual association between intracranial vessel occlusion with iron deficiency anaemia and alpha-thalassemia trait.

Matched MeSH terms: alpha-Thalassemia
Fulltext High prevalence of alpha- and beta-thalassemia in the Kadazandusuns in East Malaysia: challenges in providing effective health care for an indigenous group

Tan JA, Lee PC, Wee YC, Tan KL, Mahali NF, George E, et al.

J Biomed Biotechnol, 2010;2010.
PMID: 20871816 DOI: 10.1155/2010/706872

Thalassemia can lead to severe transfusion-dependent anemia, and it is the most common genetic disorder in Malaysia. This paper aims to determine the prevalence of thalassemia in the Kadazandusuns, the largest indigenous group in Sabah, East Malaysia. α- and β-thalassemia were confirmed in 33.6% and 12.8%, of the individuals studied respectively. The high prevalence of α- and β-thalassemia in the Kadazandusuns indicates that thalassemia screening, genetic counseling, and prenatal diagnosis should be included as part of their healthcare system. This preliminary paper serves as a baseline for further investigations into the health and genetic defects of the major indigenous population in Sabah, East Malaysia.

Matched MeSH terms: alpha-Thalassemia/epidemiology*
Fulltext Association of hematological analysis and α-globin genotypes among eligible blood donors in University Tunku Abdul Rahman (UTAR)

Lai Kuan Teh, Li Fang Lim, Yu Leong Teh, Tze Yan Lee, Lay Ngor Lim, Elizabeth George

Malaysian Journal of Medicine and Health Sciences, 2019;15(102):48-48.
MyJurnal

Introduction: Reduction or complete absence of α-globin chain production may result α-thalassemia. Alpha thalassemia carrier may have normal haemoglobin level and thus will be eligible as blood donor. Few complications may happen in which the carrier who donated the blood might be at risk of hypoxia and their blood components might not suitable for transfusion. Thus, it is important to screen for α-thalassemia to prevent any complications happen
after donation. The objective of this study is to investigate the interaction of red blood cell indices and α-globin genotypes among eligible blood donors in a private university, Universiti Tunku Abdul Rahman (UTAR), Malaysia. Methods: A total of 270 eligible blood donors were recruited for this study. Red cell indices were analysed using Horiba hematology analyser and α-globin genotyping was performed for seven alpha deletions, six alpha point mutations
and two alpha triplications. Results: Our study showed high prevalence of α-thalassemia carriers among the eligible blood donors (7.7%, 21/270), with all of them showed normal Hb level (>12 gm/dl). Five genotypes were detected consisting of 249 αα/αα (92.2%), 9 -α3.7/αα (3.3%), 9 --SEA/αα (3.3%), 2 -α4.2/αα (0.7%) and 1 ααCS/αα (0.4%). All α-globin genotypes showed normal Hb level with no significant difference between genotypes (p=0.167). Different
α-globin genotypes showed significant difference in RBC, MCV, MCH, MCHC, RDW and Hct/Hb ratio at the p

Matched MeSH terms: alpha-Thalassemia
A molecular epidemiologic study of thalassemia using newborns' cord blood in a multiracial Asian population in Singapore: results and recommendations for a population screening program

Kham SK, Yin SK, Quah TC, Loong AM, Tan PL, Fraser A, et al.

J Pediatr Hematol Oncol, 2004 Dec;26(12):817-9.
PMID: 15591902

DNA technology provides a new avenue to perform neonatal screening tests for single-gene diseases in populations of high frequency. Thalassemia is one of the high-frequency single-gene disorders affecting Singapore and many countries in the malaria belt. The authors explored the feasibility of using PCR-based diagnostic screening on 1,116 unselected sequential cord blood samples for neonatal screening. The cord blood samples were screened for the most common reported alpha- and beta-thalassemia mutations in each ethnic group (Chinese, Malays, and Indians) in a multiracial population. The carrier frequency for alpha-thalassemia mutations was about 6.4% in the Chinese (alpha deletions = 3.9%, alpha deletions = 2.5%), 4.8% in Malays, and 5.2% in Indians. Only alpha deletions were observed in the Chinese. The carrier frequency for beta-thalassemia mutations was 2.7% in the Chinese, 6.3% in Malays, and 0.7% in Indians. Extrapolating to the population distribution of Singapore, the authors found a higher overall expected carrier frequency for alpha- and beta-thalassemia mutations of 9% compared with a previous population study of 6% by phenotype. The highly accurate results make this molecular epidemiologic screening an ideal method to screen for and prevent severe thalassemia in high-risk populations.

Matched MeSH terms: alpha-Thalassemia/ethnology; alpha-Thalassemia/genetics*; alpha-Thalassemia/epidemiology*
Fulltext Screening of concurrent alpha-thalassaemia 1 in beta-thalassaemia carriers

Chong YM, Tan JA, Zubaidah Z, Rahimah A, Kuldip K, George E

Med J Malaysia, 2006 Jun;61(2):217-20.
PMID: 16898315

Thalassaemia is an inherited blood disorder and is a significant public health problem in Malaysia, with many not knowing they carry the gene for thalassaemia. The two major forms are alpha and beta thalassaemia. An individual can co-inherit both the alpha and beta thalassaemia genes. This study determined the frequency of concurrent carriers of alpha thalassaemia in 231 beta thalassaemia carriers. Gap-PCR was done on extracted DNA of the beta thalassaemia samples to check for alpha thalassaemia 1 molecular defect. Eight (3.5%) samples were found to have concurrently inherited the alpha thalassaemia 1 (- -SEA) deletion. The significant carrier rate for alpha thalassaemia 1 indicates the need for the implementation of DNA analysis to complement thalassaemia screening in high risk populations.

Matched MeSH terms: alpha-Thalassemia/complications; alpha-Thalassemia/genetics; alpha-Thalassemia/epidemiology*
Fulltext DNA studies are necessary for accurate patient diagnosis in compound heterozygosity for Hb Adana (HBA2:c.179>A) with deletional or nondeletional α-thalassaemia

Tan JA, Kho SL, Ngim CF, Chua KH, Goh AS, Yeoh SL, et al.

Sci Rep, 2016 06 08;6:26994.
PMID: 27271331 DOI: 10.1038/srep26994

Haemoglobin (Hb) Adana (HBA2:c.179>A) interacts with deletional and nondeletional α-thalassaemia mutations to produce HbH disorders with varying clinical manifestations from asymptomatic to severe anaemia with significant hepatosplenomegaly. Hb Adana carriers are generally asymptomatic and haemoglobin subtyping is unable to detect this highly unstable α-haemoglobin variant. This study identified 13 patients with compound heterozygosity for Hb Adana with either the 3.7 kb gene deletion (-α(3.7)), Hb Constant Spring (HbCS) (HBA2:c.427T>C) or Hb Paksé (HBA2:429A>T). Multiplex Amplification Refractory Mutation System was used for the detection of five deletional and six nondeletional α-thalassaemia mutations. Duplex-PCR was used to confirm Hb Paksé and HbCS. Results showed 84.6% of the Hb Adana patients were Malays. Using DNA studies, compound heterozygosity for Hb Adana and HbCS (α(codon 59)α/α(CS)α) was confirmed in 11 patients. A novel point in this investigation was that DNA studies confirmed Hb Paksé for the first time in a Malaysian patient (α(codon 59)α/α(Paksé)α) after nine years of being misdiagnosis with Hb Adana and HbCS (α(codon 59)α/α(CS)α). Thus, the reliance on haematology studies and Hb subtyping to detect Hb variants is inadequate in countries where thalassaemia is prevalent and caused by a wide spectrum of mutations.

Matched MeSH terms: alpha-Thalassemia/diagnosis*; alpha-Thalassemia/genetics
Fulltext Analysis of α1 and α2 globin genes among patients with hemoglobin Adana in Malaysia

Lee TY, Lai MI, Ismail P, Ramachandran V, Tan JA, Teh LK, et al.

Genet. Mol. Res., 2016 Apr 07;15(2).
PMID: 27173219 DOI: 10.4238/gmr.15027400

Hemoglobin (Hb) Adana [HBA2: c179G>A (or HBA1); p.Gly60Asp] is a non-deletional α-thalassemia variant found in Malaysia. An improvement in the molecular techniques in recent years has made identification of Hb Adana much easier. For this study, a total of 26 Hb Adana α-thalassemia intermedia and 10 Hb Adana trait blood samples were collected from patients. Common deletional and non-deletional α-thalassemia genotypes were determined using multiplex gap polymerase chain reaction (PCR) and multiplex ARMS PCR techniques. Identification of the Hb Adana location on the α-globin gene was carried out using genomic sequencing and the location of the mutation was confirmed via restriction fragment length polymorphism-PCR. Among the 36 samples, 24 (66.7%) had the -α(3.7)/α(Cd59)α mutation, while the -α(3.7)/α(Cd59)α mutation accounted for 2 samples (5.6%) and the remaining 10 (27.8%) samples were α/α(Cd59)α. All 36 samples were found to have the Hb Adana mutation on the α2-globin gene. The position of the α-globin gene mutation found in our cases was similar to that reported in Indonesia (16%) but not to that in Turkey (0.6%). Our results showed that the Hb Adana mutation was preferentially present in the α2-globin genes in Malays compared to the other ethnicities in Malaysia. Thus, the Malays might have similar ancestry based on the similarities in the Hb Adana position.

Matched MeSH terms: alpha-Thalassemia/ethnology; alpha-Thalassemia/genetics*
Beta-thalassaemia mutations in west Malaysia: a new thalassaemia clinical score system

George E

Ann Acad Med Singap, 1994 Jan;23(1):89-93.
PMID: 7514384

The clinical severity of the mutations causing beta-thalassaemia in West Malaysia is presented. Thalassaemia clinical scores (Thal CS), a scoring system, has been formulated to predict clinical severity. It is the type of beta-thalassaemia mutation present that decides on the clinical phenotype. The most severe beta-thalassaemia mutation is assigned a score of 4. A score of 8 indicates a severe thalassaemia phenotype. Alpha-thalassaemia, increased synthesis of Hb F, and glucose-6-phosphate deficiency may ameliorate the clinical condition at phenotype level, and the co-inheritance of hereditary ovalocytosis aggravates it.

Matched MeSH terms: alpha-Thalassemia/diagnosis
Rapid detection of α-thalassaemia variants using droplet digital PCR

Lee TY, Lai MI, Ramachandran V, Tan JA, Teh LK, Othman R, et al.

Int J Lab Hematol, 2016 Aug;38(4):435-43.
PMID: 27349818 DOI: 10.1111/ijlh.12520

INTRODUCTION: Alpha thalassaemia is a highly prevalent disease globally and is a well-known public health problem in Malaysia. The deletional forms of the mutation are the most common forms found in alpha thalassaemia. The three most common deletional alpha thalassaemia found in this region include --(SEA) deletion, -α(3.7) rightward and -α(4.2) leftward deletions. The prevalence rate of triplication alpha cases such as ααα(anti3.7) and ααα(anti4.2) is not known in Malaysia although it plays a role in exacerbating the clinical phenotypes in beta thalassaemia carriers. Recently, there have been more reported cases of rare alpha thalassaemia mutations due to the advancement of molecular techniques involved in thalassaemia detections. Therefore, it is essential to develop a new method which allows the detection of different alpha thalassaemia mutations including the rare ones simultaneously and accurately.
METHODS: The purpose of this study was to design an assay for the detection of triplications, common and rare deletional alpha thalassaemia using droplet digital PCR (ddPCR).
RESULTS: This is a quantitative detection method to measure the changes of copy number which can detect deletions, duplications and triplications of the alpha globin gene simultaneously.
CONCLUSION: In conclusion, ddPCR is an alternative method for rapid detection of alpha thalassaemia variants in Malaysia.

Matched MeSH terms: alpha-Thalassemia/genetics*; alpha-Thalassemia/epidemiology
Thalassemia intermedia in HbH-CS disease with compound heterozygosity for beta-thalassemia: challenges in hemoglobin analysis and clinical diagnosis

Tan JA, Kok JL, Tan KL, Wee YC, George E

Genes Genet Syst, 2009 Feb;84(1):67-71.
PMID: 19420802

Co-inheritance of alpha-thalassemia with homozygosity or compound heterozygosity for beta-thalassemia may ameliorate beta-thalassemia major. A wide range of clinical phenotypes is produced depending on the number of alpha-thalassemia alleles (-alpha/alphaalpha --/alphaalpha, --/-alpha). The co-inheritance of beta-thalassemia with alpha-thalassemia with a single gene deletion (-alpha/alphaalpha) is usually associated with thalassemia major. In contrast, the co-inheritance of beta-thalassemia with two alpha-genes deleted in cis or trans (--/alphaalpha or -alpha/-alpha) generally produces beta-thalassemia intermedia. In Southeast Asia, the most common defect responsible for alpha-thalassemia is the Southeast Asian (SEA) deletion of 20.5 kilobases. The presence of the SEA deletion with Hb Constant Spring (HbCS) produces HbH-CS disease. Co-inheritance of HbH-CS with compound heterozygosity for beta-thalassemia is very rare. This study presents a Malay patient with HbH-CS disorder and beta degrees/beta+-thalassemia. The SEA deletion was confirmed in the patient using a duplex-PCR. A Combine-Amplification Refractory Mutation System (C-ARMS) technique to simultaneously detect HbCS and Hb Quong Sze confirmed HbCS in the patient. Compound heterozygosity for CD41/42 and Poly A was confirmed using the ARMS. This is a unique case as the SEA alpha-gene deletion in cis (--SEA/alphaalpha) is generally not present in the Malays, who more commonly possess the two alpha-gene deletion in trans (-alpha/-alpha). In addition, the beta-globin gene mutation at CD41/42 is a common mutation in the Chinese and not in the Malays. The presence of both the SEA deletion and CD41/42 in the mother of the patient suggests the possible introduction of these two defects into the family by marriage with a Chinese.

Matched MeSH terms: alpha-Thalassemia/complications; alpha-Thalassemia/diagnosis*; alpha-Thalassemia/genetics*
Genetic problems and genetic services in Malaysia: a country report

Hassan K

Southeast Asian J. Trop. Med. Public Health, 1995;26 Suppl 1:11-5.
PMID: 8629087
Matched MeSH terms: alpha-Thalassemia/epidemiology*
Fulltext Distribution of alpha thalassaemia gene variants in diverse ethnic populations in malaysia: data from the institute for medical research

Ahmad R, Saleem M, Aloysious NS, Yelumalai P, Mohamed N, Hassan S

Int J Mol Sci, 2013;14(9):18599-614.
PMID: 24025420 DOI: 10.3390/ijms140918599

Alpha thalassaemia is highly prevalent in the plural society of Malaysia and is a public health problem. Haematological and molecular data from 5016 unrelated patients referred from various hospitals to the Institute for Medical Research for α thalassaemia screening from 2007 to 2010 were retrieved. The aims of this retrospective analysis were to describe the distribution of various alpha thalassaemia alleles in different ethnic groups, along with their genotypic interactions, and to illustrate the haematological changes associated with each phenotype. Amongst the patients, 51.2% (n = 2567) were diagnosed with α thalassaemia. Of the 13 α thalassaemia determinants screened, eight different deletions and mutations were demonstrated: three double gene deletions, --(SEA), --(THAI), --(FIL); two single-gene deletions, α-³·⁷ and -α⁴·²; and three non-deletion mutations, Cd59G > A (haemoglobin [Hb] Adana), Cd125T > C (Hb Quong Sze) and Cd142 (Hb Constant Spring). A high incidence of α-³·⁷ deletion was observed in Malays, Indians, Sabahans, Sarawakians and Orang Asli people. However, the --SEA deletion was the most common cause of alpha thalassaemia in Chinese, followed by the α-³·⁷ deletion. As many as 27 genotypic interactions showed 1023 α thalassaemia silent carriers, 196 homozygous α⁺ thalassaemia traits, 973 heterozygous α⁰ thalassaemia carriers and 375 patients with Hb H disease. Statistical analysis showed a significant difference in the distribution of α thalassaemia determinants amongst the various ethnic groups. Hence, the heterogeneous distribution of common determinants indicated that the introduction of an ethnicity-targeted hierarchical α thalassaemia screening approach in this multi-ethnic Malaysian population would be effective.

Matched MeSH terms: alpha-Thalassemia/genetics*
Fulltext Peripheral haemolysis, lipid peroxidation, iron status, and vitamin E in haemoglobin H syndromes in West Malaysia

George E, Wong HB, Jamaluddin M, Huisman TH

Singapore Med J, 1993 Jun;34(3):241-4.
PMID: 8266182

Following complete DNA characterisation patients with Hb H disease were assigned into two groups: deletional (alpha +/alpha o) and non deletional (HbCS/alpha o). Earlier studies have indicated that the group with (HbCS/alpha o) has more severe clinical problems. The serum malonyldialdehyde (MDA) levels, a secondary product of lipid peroxidation were within the normal range, though significantly higher levels of MDA were seen in the non-deletional type of Hb H disease when compared with the deletional type. Markedly low vitamin E levels were also seen in the former group. There were no significant differences in clinical severity may be attributed to an interplay of the accelerated destruction of damaged mature red blood cells secondary to the oxidative denaturation of Hb H and inclusion precipitation; higher levels of Hb H and more inclusion precipitation were seen in the group with (HbCS/alpha o). Low levels of vitamin E in the (HbCS/alpha o) group being due to its consumption in the neutralisation of free radicals formed with the oxidation of globin chains.

Matched MeSH terms: alpha-Thalassemia/blood*; alpha-Thalassemia/drug therapy; alpha-Thalassemia/genetics*
Fulltext α-Thalassemia with Haemoglobin Adana mutation: prenatal diagnosis

Zainal NZ, Alauddin H, Ahmad S, Hussin NH

Malays J Pathol, 2014 Dec;36(3):207-11.
PMID: 25500521

Thalassaemia carriers are common in the Asian region including Malaysia. Asymptomatic patients can be undiagnosed until they present for their antenatal visits. Devastating obstetric outcome may further complicate the pregnancy if both parents are thalassaemia carriers leading to hydrophic fetus due to haemoglobin Bart's disease. However in certain cases where unexplained hydrops fetalis occur in parents with heterozygous thalassaemia carrier,mutated α genes should be suspected. We report a twenty-nine year old woman in her third pregnancy with two previous pregnancies complicated by early neonatal death at 21 and 28 weeks of gestation due to hydrops fetalis. DNA analysis revealed the patient to have heterozygous (--SEA) α-gene deletion, while her husband has a compound heterozygosity for α(3.7) deletion and codon 59 (GGC → GAC) mutation of the α-gene. This mutation, also known as hemoglobin Adana, can explain hydrops fetalis resulting from two alpha gene deletions from the patient (mother) and a single alpha gene deletion with mutation from the father. The third pregnancy resulted in a grossly normal baby boy with 3 α-gene deletions (HbH disease). We postulate that, in view of heterogenisity of the α-thalassaemia in this patient with severely unstable haemoglobin Adana chains from her husband, there will be a 25% possibility of fetal hydrops in every pregnancy.

Matched MeSH terms: alpha-Thalassemia/diagnosis; alpha-Thalassemia/genetics*
Fulltext Detection of α-thalassaemia in neonates on cord blood and dried blood spot samples by capillary electrophoresis

Alauddin H, Langa M, Mohd Yusoff M, Raja Sabudin RZA, Ithnin A, Abdul Razak NF, et al.

Malays J Pathol, 2017 Apr;39(1):17-23.
PMID: 28413201 MyJurnal

INTRODUCTION: Haemoglobin Bart's (Hb Bart's) level is associated with α-thalassaemia traits in neonates, enabling early diagnosis of α-thalassaemia. The study aimed to detect and quantify the Hb Bart's using Cord Blood (CB) and CE Neonat Fast Hb (NF) progammes on fresh and dried blood spot (DBS) specimen respectively by capillary electrophoresis (CE).

METHODS: Capillarys Hemoglobin (E) Kit (for CB) and Capillarys Neonat Hb Kit (for NF) were used to detect and quantify Hb Bart's by CE in fresh cord blood and dried blood spot (DBS) specimens respectively. High performance liquid chromatography (HPLC) using the β-Thal Short Programme was also performed concurrently with CE analysis. Confirmation was obtained by multiplex ARMS Gap PCR.

RESULTS: This study was performed on 600 neonates. 32/600 (5.3%) samples showed presence of Hb Bart's peak using the NF programme while 33/600 (5.5%) were positive with CB programme and HPLC methods. The range of Hb Bart's using NF programme and CB programme were (0.5-4.1%) and (0.5-7.1%), respectively. Molecular analysis confirmed all positive samples possessed α-thalassaemia genetic mutations, with 23/33 cases being αα/--SEA, four -α3.7/-α3.7, two αα/-α3.7 and three αα/ααCS. Fifty Hb Bart's negative samples were randomly tested for α-genotypes, three were also found to be positive for α-globin gene mutations. Thus, resulting in sensitivity of 91.7% and 88.9% and specificity of 100% for the Capillarys Cord Blood programme and Capillarys Neonat Fast programme respectively.

CONCLUSION: Both CE programmes using fresh or dried cord blood were useful as a screening tool for α-thalassaemia in newborns. All methods show the same specificity (100%) with variable, but acceptable sensitivities in the detection of Hb Bart.

Matched MeSH terms: alpha-Thalassemia/diagnosis*
Fulltext Prenatal diagnosis of Hb Bart's hydrops fetalis in West Malaysia: the identification of the alpha thal 1 defect by PCR based strategies

George E, Mokhtar AB, Azman ZA, Hasnida K, Saripah S, Hwang CM

Singapore Med J, 1996 Oct;37(5):501-4.
PMID: 9046203

Haemoglobin Bart's hydrops fetalis is the result of complete absence of functional alpha-globin genes where the fetus is homozygous for the alpha 0-thal gene. Prenatal diagnosis can be made by analysis of fetal DNA from chorionic villus, amniotic cells and fetal blood. Earlier studies for analysing genomic DNA needed digestion with restriction enzymes and hybridisation to radiolabelled probes which took 2 weeks. We have used the polymerase chain reaction (PCR) and non-radioactive primers to identify specific target sequences with results available within 1-3 days for the diagnosis of haemoglobin Bart's syndrome. With fetal blood samples, complete absence of alpha-chain synthesis is confirmed by globin chain electrophoresis on cellulose acetate pH 6.0.

Matched MeSH terms: alpha-Thalassemia/diagnosis; alpha-Thalassemia/immunology
Molecular Characterisation of α- and β-Thalassaemia among Indigenous Senoi Orang Asli Communities in Peninsular Malaysia

Koh DXR, Raja Sabudin RZA, Mohd Yusoff M, Hussin NH, Ahmad R, Othman A, et al.

Ann. Hum. Genet., 2017 Sep;81(5):205-212.
PMID: 28620953 DOI: 10.1111/ahg.12201

Thalassaemia is a public health problem in Malaysia, with each ethnic group having their own common mutations. However, there is a lack on data on the prevalence and common mutations among the indigenous people. This cross-sectional study was performed to determine the common mutations of α- and β-thalassaemia among the subethnic groups of Senoi, the largest Orang Asli group in Peninsular Malaysia. Blood samples collected from six Senoi subethnic groups were analysed for full blood count and haemoglobin analysis (HbAn). Samples with abnormal findings were then screened for α- and β-globin gene mutations. Out of the 752 samples collected, 255 showed abnormal HbAn results, and 122 cases showing abnormal red cell indices with normal HbAn findings were subjected to molecular screening. DNA analysis revealed a mixture of α- and β-globin gene mutations with 25 concomitant cases. The types of gene abnormalities detected for α-thalassaemia were termination codon (T>C) Hb CS (αCS α), Cd59 (G>A) haemoglobin Adana (Hb Adana) (αCd59 α), initiation codon (ATG>A-G) (αIniCd α), two-gene deletion (-SEA ), and single-gene 3.7-kb deletion (-α3.7 ). For β-thalassaemia, there were Cd26 (G>A) Hb E (βE ), Cd19 (A>G) Haemoglobin Malay (Hb Malay) (βCd19 ), and IVS 1-5 (G>C) (βIVS 1-5 ).

Matched MeSH terms: alpha-Thalassemia/genetics*; alpha-Thalassemia/epidemiology
Microcytic to hypochromic ratio as a discriminant index of thalassaemia trait in subjects with hypochromic anaemia

Wee SY, Muhamed Said SS, Raja Sabudin RZA, Alauddin H, Ithnin A

Malays J Pathol, 2020 Aug;42(2):195-201.
PMID: 32860371

INTRODUCTION: Differentiating between thalassaemia and iron deficiency anaemia (IDA) in hypochromic anaemia is a challenge to pathologists as it influences the choice of subsequent specialized confirmatory tests. In this study, we aimed to evaluate the performance of microcytic to hypochromic ratio (MicroR/ Hypo-He, M/H ratio) as a discriminant index in hypochromic anaemia.
MATERIALS AND METHODS: A retrospective study was carried out on 318 subjects with hypochromic anaemia, which comprised 162 IDA and 156 thalassaemia trait subjects with α-thalassemia, β-thalassemia and HbE trait. Optimal cut-off value, sensitivity and specificity of M/H ratio for thalassaemia trait discrimination was determined using Receiver Operating Characteristic (ROC) analysis.
RESULTS: Subjects with thalassaemia trait showed higher MicroR compared to IDA ( p< 0.001) while subjects with IDA demonstrated higher Hypo-He than thalassaemia trait (p < 0.001). M/H ratio was significantly higher in thalassaemia trait compared to IDA, with medians of 3.77 (interquartile range: 2.57 - 6.52) and 1.73 (interquartile range: 1.27 - 2.38), respectively (p < 0.001). M/H ratio ≥ 2.25 was the optimal cut-off value for discriminating thalassaemia trait from IDA in hypochromic anaemia, with the area under ROC curve (AUC) of 0.83, sensitivity of 80.8% and specificity of 71.6%.
CONCLUSIONS: M/H ratio is a useful discriminant index to distinguish thalassaemia trait from IDA in hypochromic anaemia prior to diagnostic analysis for thalassaemia confirmation. High M/H ratio is suggestive of thalassaemia trait than of IDA. However, more studies are required to establish the role of M/H ratio as a screening tool for thalassaemia discrimination in hypochromic anaemia.

Matched MeSH terms: alpha-Thalassemia/diagnosis; alpha-Thalassemia/pathology

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