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Ruengdit C, Punyamung M, Intasai N, Pornprasert S. Single-tube multiplex real-time PCR with EvaGreen and high-resolution melting analysis for diagnosis of α0-thalassemia--SEA,--THAI, and--CR type deletions. PLoS One 2023; 18:e0293838. [PMID: 37930985 PMCID: PMC10627449 DOI: 10.1371/journal.pone.0293838] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/20/2023] [Indexed: 11/08/2023] Open
Abstract
Regions with a high prevalence of α-thalassemia (α-thal) require simple, rapid, and accurate tests for carrier screening and prenatal diagnosis. Diagnosis of multiple deletions in a single tube is necessary to clearly identify individuals with α0-thalassemia in the routine setting, especially in at-risk couples. Therefore, we aimed to develop a single-tube multiplex real-time PCR with EvaGreen and high-resolution melting (HRM) analysis for the identification of α0-thalassemia Southeast Asian (SEA), Thai and Chiang Rai (CR) type deletions. The results of the HRM analysis indicated that the amplified fragments from α0-thal--CR,--THAI,--SEA, and the wild-type α-globin gene had specific peak heights at mean melting temperature (Tm) values of 85.40°C, 86.50°C, 87.65°C, and 91.04°C, respectively. The frequencies of α0-thal--SEA,--THAI,--CR obtained from routine testing in 2,135 samples were 17.89%, 0.19% and 0.19%, respectively. This method would be useful for preventing Hb Bart's hydrops fetalis. Detection of multiple deletions in a single run is cost-effective, highly accurate and timesaving. This technique could enable wider α-thalassemia diagnosis in high prevalence areas and served as an example for thalassemia routine setting.
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Affiliation(s)
- Chedtapak Ruengdit
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Manoo Punyamung
- Associated Medical Sciences Clinical Service Center, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Nutjeera Intasai
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Sakorn Pornprasert
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
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Luewan S, Tongprasert F, Srisupundit K, Traisrisilp K, Jatavan P, Tongsong T. Fetal Hemodynamic Response to Anemia in Early Gestation: Using Hemoglobin Bart's Disease as a Study Model. ULTRASCHALL IN DER MEDIZIN (STUTTGART, GERMANY : 1980) 2023; 44:e83-e90. [PMID: 34749405 DOI: 10.1055/a-1499-7045] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
OBJECTIVE To assess fetal hemodynamic changes in response to anemia in early gestation, using fetal Hb Bart's disease as a study model. METHODS A prospective study was conducted on pregnancies at risk for fetal Hb Bart's disease at 12-14 weeks of gestation. Fetal hemodynamics were comprehensively assessed by 2D ultrasound, Doppler velocity, and cardio-STIC just prior to the invasive procedure for diagnosis. The various hemodynamic parameters of the affected and unaffected fetuses were compared. RESULTS Of 56 fetuses at risk, 17 had Hb Bart's disease and 39 were unaffected. The right and combined ventricular cardiac outputs (CO) were significantly higher in the affected fetuses (0.993 vs. 1.358; p < 0.001 and 1.010 vs. 1.236; p < 0.001, respectively), whereas the left CO tended to be higher but not significantly (1.027 vs. 1.113; p = 0.058). Cardiac dimensions, middle-cerebral artery peak systolic velocity, Tei index, and isovolemic contraction time were significantly increased, while the global sphericity index was significantly decreased. Interestingly, cardiac preload, ventricular wall thickness, shortening fraction, isovolemic relaxation time, and fetal heart rate were unchanged. Four fetuses had hydropic changes, but all cardiac functions were normal. CONCLUSION Fetal anemia induces hypervolemia and increases cardiac output to meet the tissue oxygen requirement, resulting in an increase in size without hypertrophy, volume load without pressure load, and a decrease in the globular sphericity index. The heart works very well but works harder, especially systolic ventricular load. Hydrops fetalis due to anemia appears not to be caused by heart failure as previously believed but rather by volume load with high vascular permeability at least in early pregnancy.
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Affiliation(s)
- Suchaya Luewan
- Obstetrics and Gynecology, Chiang Mai University, Chiang Mai, Thailand
| | | | | | | | - Phudit Jatavan
- Obstetrics and Gynecology, Chiang Mai University, Chiang Mai, Thailand
| | - Theera Tongsong
- Obstetrics and Gynecology, Chiang Mai University, Chiang Mai, Thailand
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Jatavan P, Sekararithi R, Jaiwongkam T, Kumfu S, Chattipakorn N, Tongsong T. Comparisons of serum non-transferrin-bound iron levels and fetal cardiac function between fetuses affected with hemoglobin Bart's disease and normal fetuses. Front Med (Lausanne) 2023; 9:1015306. [PMID: 36660002 PMCID: PMC9842659 DOI: 10.3389/fmed.2022.1015306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 11/24/2022] [Indexed: 01/04/2023] Open
Abstract
Objective To compare the levels of Non-transferrin bound iron (NTBI) in fetuses with anemia, using Hb Bart's disease as a study model, and those in unaffected fetuses and to determine the association between fetal cardiac function and the levels of NTBI. Patients and methods A prospective study was conducted on pregnancies at risk of fetal Hb Bart's disease. All fetuses underwent standard ultrasound examination at 18-22 weeks of gestation for fetal biometry, anomaly screening and fetal cardiac function. After that, 2 ml of fetal blood was taken by cordocentesis to measure NTBI by Labile Plasma Iron (LPI), serum iron, hemoglobin and hematocrit. The NTBI levels of both groups were compared and the correlation between NTBI and fetal cardiac function was determined. Results A total of 50 fetuses, including 20 fetuses with Hb Bart's disease and 30 unaffected fetuses were recruited. There was a significant increase in the level of serum iron in the affected group (median: 22.7 vs. 9.7; p-value: 0.013) and also a significant increase in NTBI when compared with those of the unaffected fetuses (median 0.11 vs. 0.07; p-value: 0.046). In comparisons of fetal cardiac function, myocardial performance (Tei) index of both sides was significantly increased in the affected group (left Tei: p = 0.001, Right Tei: p = 0.008). Also, isovolumetric contraction time (ICT) was also significantly prolonged (left ICT: p = 0.00, right ICT: p = 0.000). Fetal LPI levels were significantly correlated inversely with fetal hemoglobin levels (p = 0.030) but not significantly correlated with the fetal serum iron levels (p = 0.138). Fetal LPI levels were also significantly correlated positively with myocardial performance index (Tei) of both sides (right Tei: R = 0.000, left Tei: R = 0.000) and right ICT (R = 0.013), but not significantly correlated with left ICT (R = 0.554). Conclusion Anemia caused by fetal Hb Bart's disease in pre-hydropic stage is significantly associated with fetal cardiac dysfunction and increased fetal serum NTBI levels which are significantly correlated with worsening cardiac dysfunction. Nevertheless, based on the limitations of the present study, further studies including long-term data are required to support a role of fetal anemia as well as increased fetal serum NTBI levels in development of subsequent heart failure or cardiac compromise among the survivors, possibly predisposing to cardiovascular disease in adult life.
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Affiliation(s)
- Phudit Jatavan
- Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Rattanaporn Sekararithi
- Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Thidarat Jaiwongkam
- Cardiac Electrophysiology Research and Training Center (CERT), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Sirinart Kumfu
- Cardiac Electrophysiology Research and Training Center (CERT), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Research and Training Center (CERT), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Theera Tongsong
- Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand,*Correspondence: Theera Tongsong,
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Thammavong K, Luewan S, Tongsong T. Performance of Fetal Cardiac Volume Derived from VOCAL (Virtual Organ Computer-Aided AnaLysis) in Predicting Hemoglobin (Hb) Bart's Disease. J Clin Med 2021; 10:jcm10204651. [PMID: 34682774 PMCID: PMC8539212 DOI: 10.3390/jcm10204651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 09/28/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To determine the performance of fetal cardiac volume (CV) in the detection of fetal Hb Bart's disease among fetuses at risk at 18-22 weeks of gestation and to compare the performance with those of cardiothoracic diameter ratio (CTR) and middle cerebral artery peak systolic velocity (MCA-PSV). METHODS Fetuses at risk of Hb Bart's disease between 18 and 22 weeks of gestation prospectively underwent echocardiography with acquisition of the volume datasets (VDS) of fetal heart, using 4D-cardiac STIC. Subsequently, off-line analysis was blindly performed to measure cardiac volume using the VOCAL technique. RESULTS A total of 502 fetuses at risk meeting the inclusion criteria were included in the analysis, consisting of 117 (23.3%) fetuses with Hb Bart's disease and 385 (76.7%) unaffected fetuses. The mean (±SD) gestational age at the time of ultrasound examination was 19.70 ± 1.3 weeks. In predicting fetal Hb Bart's disease, CV, using a cut-off Z-score of 1.7, had a sensitivity of 94.9% and specificity of 94.0%. The performance of CV was slightly better than that of CTR but very superior to that of MCA-PSV (areas under curve: 0.988, 0.974 and 0.862, respectively). CONCLUSIONS Fetal CV has a very high performance in predicting fetal Hb Bart's disease at mid-pregnancy, comparable with CTR and much better than MCA-PSV.
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Adam AP, Payton KSE, Sanchez-Lara PA, Adam MP, Mirzaa GM. Hypoxia: A teratogen underlying a range of congenital disruptions, dysplasias, and malformations. Am J Med Genet A 2021; 185:2801-2808. [PMID: 33938618 DOI: 10.1002/ajmg.a.62235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/12/2021] [Accepted: 04/15/2021] [Indexed: 01/20/2023]
Abstract
In this review, we explore evidence that hypoxia in the developing human fetus can lead not only to the more commonly accepted disruptive-type defects, but also patterns of anomalies that suggest that hypoxia can exert a more classic teratogenic effect, using the brain as one example. We review neuropathology in the context of intrauterine hypoxia, particularly as it relates to carbon monoxide poisoning, in utero strokes, and homozygous alpha-thalassemia. In general, the associated brain injuries resemble those seen with other causes of hypoxic-ischemic injury. Fetal strokes during development usually lead to loss of brain tissue in areas that do not follow a typical embryologic pattern, and therefore are considered disruptions. However, there is also evidence that fetal brain ischemia can cause more classically recognized patterns of abnormal embryonic neuronal migration and organization such as polymicrogyria, cortical dysplasia, or dysgenesis, including select types of focal cortical dysplasia. This study summarizes available literature and evidence to raise clinicians' awareness regarding the association between hypoxia and congenital anomalies, including brain malformations.
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Affiliation(s)
- Aaron P Adam
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Kurlen S E Payton
- Division of Neonatology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Pedro A Sanchez-Lara
- Division of Neonatology, Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Division of Medical Genetics, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Margaret P Adam
- Divison of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Ghayda M Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Divison of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington, USA
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Lee TH, Hsu YC, Chang CL. Detection of SEA-type α-thalassemia in embryo biopsies by digital PCR. Taiwan J Obstet Gynecol 2017; 56:487-494. [DOI: 10.1016/j.tjog.2017.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2017] [Indexed: 10/19/2022] Open
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Songdej D, Babbs C, Higgs DR. An international registry of survivors with Hb Bart's hydrops fetalis syndrome. Blood 2017; 129:1251-1259. [PMID: 28057638 PMCID: PMC5345731 DOI: 10.1182/blood-2016-08-697110] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/19/2016] [Indexed: 11/20/2022] Open
Abstract
Hemoglobin (Hb) Bart's hydrops fetalis syndrome (BHFS) resulting from α0-thalassemia is considered a universally fatal disorder. However, over the last 3 decades, improvements in intrauterine interventions and perinatal intensive care have resulted in increasing numbers of BHFS survivors. We have initiated an international registry containing information on 69 patients, of which 31 are previously unpublished. In this perspective, we analyze the available clinical information to document the natural history of BHFS. In the future, once we have accrued sufficient cases, we aim to build on this study and provide information to allow counseling of at-risk couples. To date, 39 patients have survived beyond the age of 5 years, 18 of whom are now older than 10 years. Based on the available cases, we find evidence to suggest that intrauterine therapy provides benefits during the perinatal and neonatal period; however, it may not provide additional benefits to long-term growth and neurodevelopmental outcomes. Growth retardation is a major adverse long-term outcome among BHFS patients with ∼40% being severely affected in terms of weight and ∼50% in terms of height. There is also an increased risk of neurodevelopmental delay as we find 20% (11/55) of BHFS survivors suffer from a serious delay of ≥6 months. Most patients in the registry require lifelong transfusion and often have associated congenital abnormalities and comorbidities. This perspective is a first step in gathering information to allow provision of informed counseling on the predicted outcomes of affected babies.
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Affiliation(s)
- Duantida Songdej
- Medical Research Council Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom; and
- Division of Hematology/Oncology, Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Christian Babbs
- Medical Research Council Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom; and
| | - Douglas R Higgs
- Medical Research Council Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom; and
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Farashi S, Najmabadi H. Diagnostic pitfalls of less well recognized HbH disease. Blood Cells Mol Dis 2015; 55:387-95. [DOI: 10.1016/j.bcmd.2015.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/06/2015] [Accepted: 08/06/2015] [Indexed: 10/23/2022]
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Pornprasert S, Prasing W. Detection of alpha(0)-thalassemia South-East Asian-type deletion by droplet digital PCR. Eur J Haematol 2014; 92:244-8. [PMID: 24330258 DOI: 10.1111/ejh.12246] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND The α(0)-thalassemia South-East Asian (SEA)-type deletion is the most common genetic disorder in the Asian population. Couples who are both carriers have a 25% chance of conceiving Bart's hydrops fetalis. Therefore, results from carrier screening and prenatal diagnosis frequently need to be available rapidly. The aim of this study was to implement a droplet digital polymerase chain reaction (ddPCR) for diagnosis of α(0)-thalassemia SEA-type deletion. METHODS The wild-type α-globin gene allele and α(0)-thalassemia SEA allele were quantified in DNA samples of 20 normal individuals, 15 samples with α(0)-thalassemia SEA trait, and 8 samples with Bart's hydrops fetalis using the ddPCR. The DNA copy number of wild-type α-globin gene allele and α(0)-thalassemia SEA allele was then calculated using the Quantasoft analysis software. RESULTS The mean ± standard deviation (SD) ratio of wild-type α-globin gene allele and α(0)-thalassemia SEA allele among normal individuals, samples with α(0)-thalassemia SEA trait, and Bart's hydrops fetalis were clearly distinguished with levels of 1.78 ± 0.49, 0.85 ± 0.14, and 0.03 ± 0.03, respectively. CONCLUSION The ddPCR may be one alternative technology available for routine clinical diagnosis of α(0)-thalassemia SEA-type deletion and prenatal diagnosis of Bart's hydrops fetalis.
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Affiliation(s)
- Sakorn Pornprasert
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
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Pornprasert S, Wiengkum T, Srithep S, Chainoi I, Singboottra P, Wongwiwatthananukit S. Detection of α-thalassemia-1 Southeast Asian and Thai type deletions and β-thalassemia 3.5-kb deletion by single-tube multiplex real-time PCR with SYBR Green1 and high-resolution melting analysis. Korean J Lab Med 2011; 31:138-42. [PMID: 21779184 PMCID: PMC3129341 DOI: 10.3343/kjlm.2011.31.3.138] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 01/16/2011] [Accepted: 03/25/2011] [Indexed: 11/19/2022] Open
Abstract
Background Prevention and control of thalassemia requires simple, rapid, and accurate screening tests for carrier couples who are at risk of conceiving fetuses with severe thalassemia. Methods Single-tube multiplex real-time PCR with SYBR Green1 and high-resolution melting (HRM) analysis were used for the identification of α-thalassemia-1 Southeast Asian (SEA) and Thai type deletions and β-thalassemia 3.5-kb gene deletion. The results were compared with those obtained using conventional gap-PCR. DNA samples were derived from 28 normal individuals, 11 individuals with α-thalassemia-1 SEA type deletion, 2 with α-thalassemia-1 Thai type deletion, and 2 with heterozygous β-thalassemia 3.5-kb gene deletion. Results HRM analysis indicated that the amplified fragments from α-thalassemia-1 SEA type deletion, α-thalassemia-1 Thai type deletion, β-thalassemia 3.5-kb gene deletion, and the wild-type β-globin gene had specific peak heights at mean melting temperature (Tm) values of 86.89℃, 85.66℃, 77.24℃, and 74.92℃, respectively. The results obtained using single-tube multiplex real-time PCR with SYBR Green1 and HRM analysis showed 100% consistency with those obtained using conventional gap-PCR. Conclusions Single-tube multiplex real-time PCR with SYBR Green1 and HRM analysis is a potential alternative for routine clinical screening of the common types of α- and β-thalassemia large gene deletions, since it is simple, cost-effective, and highly accurate.
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Affiliation(s)
- Sakorn Pornprasert
- Department of Medical Technology, Chiang-Mai University, Chiang-Mai, Thailand.
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Srisupundit K, Tongprasert F, Luewan S, Sirichotiyakul S, Tongsong T. Splenic circumference at midpregnancy as a predictor of hemoglobin Bart's disease among fetuses at risk. Gynecol Obstet Invest 2011; 72:63-7. [PMID: 21389673 DOI: 10.1159/000323540] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 11/22/2010] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To determine the accuracy of splenic circumference in predicting hemoglobin (Hb) Bart's disease among fetuses at risk at midpregnancy. MATERIALS AND METHODS Women with singleton pregnancies with a fetal risk of Hb Bart's disease were enrolled in the study at 18-22 weeks of gestation. All underwent splenic circumference measurement before cordocentesis for fetal blood analysis. The final diagnosis used as a gold standard was based on fetal Hb typing using high-performance liquid chromatography. RESULTS Among all the pregnancies, the prevalence of Hb Bart's disease was 26.1% (87/334 fetuses). Twenty-four fetuses (27.6%) had some degree of hydropic changes. Notably, of these 24, 22 showed splenomegaly as well. When hydropic fetuses were excluded, the sensitivity, specificity, positive predictive value and negative predictive value of splenic circumference in identifying affected fetuses were 68.3, 83.0, 50.6 and 91.1%, respectively. CONCLUSION Splenic circumference measurement at midpregnancy may be helpful in distinguishing affected fetuses from those unaffected. Among couples at risk with normal splenic size, the risk of having an affected child is much lower, whereas the enlarged spleen places the pregnancy at a higher risk. This information may help couples decide on invasive diagnosis or a noninvasive approach.
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Affiliation(s)
- Kasemsri Srisupundit
- Department of Obstetrics and Gynecology, Maharaj Nakorn Chiang Mai Hospital, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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Fetal liver length measurement at mid-pregnancy among fetuses at risk as a predictor of hemoglobin Bart's disease. J Perinatol 2011; 31:157-60. [PMID: 20651692 DOI: 10.1038/jp.2010.84] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To assess the effectiveness of liver length measurement in predicting hemoglobin (Hb) Bart's disease among fetuses at risk at mid-pregnancy. STUDY DESIGN Pregnant women at risk of fetal Hb Bart's disease at 18 to 22 weeks of gestation were enrolled in the study. All of them underwent liver length measurement just before cordocentesis for fetal blood analysis. The final diagnosis used as a gold standard was based on fetal Hb typing using high-performance liquid chromatography. RESULT A total of 334 pregnant women were recruited into the study. The prevalence of fetal Hb Bart's disease was 26.1% (87 of 334 fetuses). The sensitivity, specificity, as well as positive and negative predictive values of liver length in the prediction of affected fetuses were 71.3, 95.5, 84.9 and 90.4%, respectively. Overall, 24 fetuses (27.6%) had some degree of early hydrops fetalis. Of these, 20 had hepatomegaly as well. CONCLUSION Liver length measurements at mid-pregnancy may be helpful in predicting affected fetuses among pregnancies at risk. Normal liver length measurement is associated with a very low risk of the disease. This information may help couples decide on whether to opt for either invasive diagnosis or a noninvasive approach, especially when used as an adjunct to other tests.
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Vichinsky E. Complexity of alpha thalassemia: growing health problem with new approaches to screening, diagnosis, and therapy. Ann N Y Acad Sci 2010; 1202:180-7. [PMID: 20712791 DOI: 10.1111/j.1749-6632.2010.05572.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Alpha thalassemia, the most common genetic disorder of hemoglobin synthesis, affects up to 5% of the world's population. It represents a group of conditions with reduced or absent synthesis of one to all four of alpha globin genes. Deletional or nondeletional mutations occur on chromosome 16. Its severity ranges from asymptomatic to fatal in utero. Hemoglobin H disease, a mutation of three alpha globin genes, is more severe than previously recognized. Anemia, hypersplenism, hemosiderosis, growth failure, and osteoporosis are commonly noted as the patient ages. Alpha thalassemia major, a usually fatal in utero disease, is now recognized to have a complex molecular and phenotypic expression with increasing births being reported. Surviving newborns without intrauterine transfusion often have congenital anomalies and neurocognitive injury. Serious maternal complications often accompany pregnancy. Doppler ultrasonography with intrauterine transfusion ameliorates these complications. The high incidence in many populations mandates population screening and prenatal diagnosis of at-risk couples. Universal newborn screening has been adopted in several regions with DNA confirmatory testing. These advances have resulted in ethical dilemmas for the family and the provider.
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Affiliation(s)
- Elliott Vichinsky
- Children's Hospital & Research Center Oakland, Oakland, Califorina, USA.
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Wang W, Yap CHA, Loh SF, Tan ASC, Lim MN, Prasath EB, Chan MLH, Tan WC, Jiang B, Yeo GH, Mathew J, Ho A, Ho SSY, Wong PC, Choolani MA, Chong SS. Simplified PGD of common determinants of haemoglobin Bart's hydrops fetalis syndrome using multiplex-microsatellite PCR. Reprod Biomed Online 2010; 21:642-8. [PMID: 20864413 DOI: 10.1016/j.rbmo.2010.06.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 06/03/2010] [Accepted: 06/08/2010] [Indexed: 12/29/2022]
Abstract
The high incidence of double-gene deletions in α-thalassaemia increases the risk of having pregnancies with homozygous α(0)-thalassaemia, the cause of the lethal haemoglobin (Hb) Bart's hydrops fetalis syndrome. Preimplantation genetic diagnosis (PGD) has played an important role in preventing such cases. However, the current gap-PCR based PGD protocol for deletional α-thalassaemia requires specific primer design for each specific deletion. A universal PGD assay applicable to all common deletional determinants of Hb Bart's hydrops fetalis syndrome has been developed. Microsatellite markers 16PTEL05 and 16PTEL06 within the α-globin gene cluster were co-amplified with a third microsatellite marker outside the affected region in a multiplex-PCR reaction and analysed by capillary electrophoresis. Eight informed couples at risk of having Hb Bart's hydrops fetalis were recruited in this study and all patients underwent standard procedures associated with IVF. A total of 47 embryos were analysed. Three pregnancies were achieved from three couples, with the births of two healthy babies and one ongoing pregnancy. This work has successfully adapted an earlier protocol and developed a simple and reliable single-cell assay applicable to PGD of Hb Bart's hydrops fetalis syndrome regardless of type of deletion. Alpha-thalassaemia is one of the most common inheritable disorders worldwide. It is a blood disorder that, in its lethal form caused by deletion of all four copies of the α-globin gene, results in the demise of the affected fetus, a condition referred to as haemoglobin (Hb) Bart's hydrops fetalis syndrome. Preimplantation genetic diagnosis (PGD) has played an important role in preventing such cases. Current PGD protocols for deletional α-thalassaemia utilize a strategy called gap-PCR, which requires the different assays for different deletion types. We have developed a universal PGD assay applicable to all common deletional determinants of Hb Bart's hydrops fetalis syndrome based on microsatellite marker analysis. Eight informed couples at risk of having Hb Bart's hydrops fetalis were recruited in this study and all patients underwent standard procedures associated with IVF. Forty-five embryos were analysed in total. Three pregnancies were achieved from three couples, with the births of two healthy babies and one pregnancy still ongoing. We have successfully adapted our earlier protocol and developed a simple and reliable single cell assay applicable to PGD of Hb Bart's hydrops fetalis syndrome regardless of the type of deletion.
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Affiliation(s)
- Wen Wang
- Preimplantation Genetic Diagnosis Center, University Children's Medical Institute, Department of Pediatrics, Yong Loo Lin School of Medicine, National University Health System, Singapore 119074, Singapore
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Abstract
Alpha-thalassaemia is inherited as an autosomal recessive disorder characterised by a microcytic hypochromic anaemia, and a clinical phenotype varying from almost asymptomatic to a lethal haemolytic anaemia. It is probably the most common monogenic gene disorder in the world and is especially frequent in Mediterranean countries, South-East Asia, Africa, the Middle East and in the Indian subcontinent. During the last few decades the incidence of alpha thalassaemia in North-European countries and Northern America has increased because of demographic changes. Compound heterozygotes and some homozygotes have a moderate to severe form of alpha thalassaemia called HbH disease. Hb Bart's hydrops foetalis is a lethal form in which no alpha-globin is synthesized. Alpha thalassaemia most frequently results from deletion of one or both alpha genes from the chromosome and can be classified according to its genotype/phenotype correlation. The normal complement of four functional alpha-globin genes may be decreased by 1, 2, 3 or all 4 copies of the genes, explaining the clinical variation and increasing severity of the disease. All affected individuals have a variable degree of anaemia (low Hb), reduced mean corpuscular haemoglobin (MCH/pg), reduced mean corpuscular volume (MCV/fl) and a normal/slightly reduced level of HbA2. Molecular analysis is usually required to confirm the haematological observations (especially in silent alpha-thalassaemia and alpha-thalassaemia trait). The predominant features in HbH disease are anaemia with variable amounts of HbH (0.8-40%). The type of mutation influences the clinical severity of HbH disease. The distinguishing features of the haemoglobin Bart's hydrops foetalis syndrome are the presence of Hb Bart's and the total absence of HbF. The mode of transmission of alpha thalassaemia is autosomal recessive. Genetic counselling is offered to couples at risk for HbH disease or haemoglobin Bart's Hydrops Foetalis Syndrome. Carriers of alpha+- or alpha0-thalassaemia alleles generally do not need treatment. HbH patients may require intermittent transfusion therapy especially during intercurrent illness. Most pregnancies in which the foetus is known to have the haemoglobin Bart's hydrops foetalis syndrome are terminated due to the increased risk of both maternal and foetal morbidity.
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Affiliation(s)
- Cornelis L Harteveld
- 1Department of Human and Clinical Genetics, Leiden University Medical Center, Einthovenweg 20, 2333ZC Leiden, The Netherlands
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17
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Abstract
PURPOSE OF REVIEW This review will inform the clinician about the application, success rates and limitations of preimplantation genetic diagnosis (PGD) for haematologic disease to enable clinicians to offer couples with reproductive risk a realistic view of possible treatments. The molecular techniques used to diagnose disease mutations are described, including the newest technologies using whole genome amplification (WGA) and preimplantation genetic haplotyping (PGH) of embryos. The history and ethics involved in performing PGD together with human leukocyte antigen (HLA) testing (PGD-H) to create matched siblings suitable for haematopoietic stem cell transplant (HSCT) are discussed. RECENT FINDINGS The greatest diagnostic hurdle in PGD is the paucity of molecular material in the single embryonic cell. WGA allows amplification of the entire genome, which greatly simplifies mutation analysis and increases the possibilities of multiple simultaneous genetic diagnoses. PGH can be applied to the amplified material, and may enable the application of PGD to the less common haematological mutations, and the diagnosis of nonaffected male progeny in cases of X-linked haematologic diseases. SUMMARY PGD to exclude embryos carrying serious haematologic disease is a viable alternative to prenatal diagnosis for couples who wish to avoid having affected children and for whom therapeutic termination of affected pregnancies is unacceptable. PGD is not available for all haematologic mutations, is expensive, time consuming and does not guarantee a pregnancy. PGD-H is more diagnostically and ethically challenging, especially when there is the time constraint of urgent provision of HLA-matched stem cells for a sick sibling. To date there is only a handful of reported cases of successful HSCT from siblings created by embryo selection. The evolving technology of PGH following WGA may increase the diagnostic scope and availability of PGD in the future, but certain limitations will remain.
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Vichinsky EP. Alpha thalassemia major--new mutations, intrauterine management, and outcomes. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2009; 2009:35-41. [PMID: 20008180 DOI: 10.1182/asheducation-2009.1.35] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Alpha thalassemia disorders are a group of hereditary anemias caused by absent or decreased production of the alpha chain of hemoglobin. Hemoglobin Bart's hydrops fetalis is usually a fatal in-utero disease caused by absence of the alpha genes. However, the molecular and genotypic expression of hemoglobin Bart's varies and increasing numbers of births are being reported. Population screening and prenatal diagnosis of at-risk couples is essential but often not performed. Most affected pregnancies are often undetected, resulting in severe fetal and maternal complications. Noninvasive monitoring by Doppler ultrasonagraphy with intrauterine transfusion therapy has changed the prognosis for this disorder. These advances in intrauterine and postnatal therapy have resulted in ethical dilemmas for the family and the provider.
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Pornprasert S, Sukunthamala K, Sacome J, Phusua A, Saetung R, Sanguansermsri T, Leechanachai P. Analysis of real-time SYBR-polymerase chain reaction cycle threshold for diagnosis of the alpha-thalassemia-1 Southeast Asian type deletion: application to carrier screening and prenatal diagnosis of Hb Bart's hydrops fetalis. Hemoglobin 2008; 32:393-402. [PMID: 18654890 DOI: 10.1080/03630260701798367] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Without gel electrophoresis and specific probes, the two tubes real-time SYBR-polymerase chain reaction (SYBR-PCR) was setup by using different primer sets: P1/P2 for the detection of wild type alpha-globin gene alleles and P1/P3 for detection of the allele bearing the Southeast Asian (SEA) type (--SEA) deletion. Analyses of the cycle threshold (CT) values obtained by each primer set together with a delta-cycle threshold (DeltaCT) and CT ratio, showed that lower CT values generated by primer sets P1/P2 and P1/P3 were observed in normal and Hb Bart's hydrops fetalis subjects, respectively. In heterozygous subjects the CT values generated by both sets of primers were similar to each other. There was no overlapping of DeltaCT and CT ratio between normal, heterozygous and Hb Bart's hydrops fetalis subjects. Therefore, the two tubes real-time SYBR-PCR could represent a rapid, cost effective, high-throughput assay for screening of carriers and prenatal diagnosis of alpha-thalassemia-1 (alpha-thal-1) with the SEA type (--SEA) deletion.
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Affiliation(s)
- Sakorn Pornprasert
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang-Mai University, Chiang-Mai, Thailand
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Pornprasert S, Phusua A, Suanta S, Saetung R, Sanguansermsri T. Detection of alpha-thalassemia-1 Southeast Asian type using real-time gap-PCR with SYBR Green1 and high resolution melting analysis. Eur J Haematol 2008; 80:510-4. [PMID: 18284625 DOI: 10.1111/j.1600-0609.2008.01055.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alpha-thalassemia-1 Southeast Asian (SEA) type is the most common genetic disorder in the Asian population. Couples who are both carriers have a 25% chance of conceiving Bart's hydrops fetalis. Therefore, results from carrier screening and prenatal diagnosis frequently need to be available rapidly. A rapid technique for diagnosis of alpha-thalassemia-1 SEA type was implemented. The technique used is based on real-time gap-PCR and high resolution melting (HRM) analysis of the amplified fragment using the Rotor-Gene 6000. The DNA samples used for amplification were obtained from whole blood, cord blood, and chorionic villus sampling (CVS). With this method, the alpha-thalassemia-1 SEA allele can be easily distinguished from wild type alpha-globin gene allele. The real-time gap-PCR and HRM analysis offers additional benefits including minimal labor, rapid turnaround time, and a decreased risk of PCR carryover contamination. It is cost-effective and safe, does not require fluorescently labeled probe and hazardous chemicals. Moreover, it is accurate showing 100% concordance with conventional gap-PCR analysis.
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Affiliation(s)
- Sakorn Pornprasert
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang-Mai University, Chiang-Mai, Thailand.
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21
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Abstract
Anemia is a commonly encountered problem in the fetal and neonatal period, and can lead to significant morbidity and mortality. Intrinsic disorders of the erythrocyte, such as the hemoglobinopathies, enzyme deficiencies, and membrane defects are common causes of neonatal anemia. Genetic diseases that lead to decreased erythrocyte production, such as Diamond-Blackfan anemia, Schwachman-Diamond syndrome, and Congential Dyserythropoietic Anemia, are rare causes of perinatal anemia, but are important to recognize as they are often associated with other congenital abnormalities and require specialized treatment. This review focuses on the perinatal presentation and management of intrinsic erythrocyte disorders, as well as on the diagnosis and management of genetic conditions leading to erythrocyte underproduction.
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Affiliation(s)
- Laurie A Steiner
- Division of Perinatal Medicine, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520-8064, USA.
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Siriratmanawong N, Pinmuang-Ngam C, Fucharoen G, Fucharoen S. Prenatal diagnosis of Hb Bart's hydrops fetalis caused by a genetic compound heterozygosity for two different alpha-thalassemia determinants. Fetal Diagn Ther 2007; 22:264-8. [PMID: 17369692 DOI: 10.1159/000100787] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Accepted: 06/07/2006] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To describe prenatal diagnosis of hemoglobin (Hb) Bart's hydrops fetalis caused by a previously undescribed condition in Thailand of the interaction of alpha(o)-thalassemia with the Southeast Asian (-(SEA)) and the THAI (-(THAI)) deletions in a Thai family. METHODS Molecular and hematological features associated with alpha(o)-thalassemia carriers found in a pregnant Thai woman and her husband were investigated. Prenatal diagnosis was performed at her third pregnancy on amniotic fluid using a multiplex PCR for simultaneous detection of the (-(SEA)) and (-(THAI)) alpha(o)-thalassemia determinants. RESULTS Initial DNA analysis for the common form of alpha(o)-thalassemia (-(SEA)) identified that the pregnant woman was a carrier whereas her husband was negative for this mutation. They had a healthy non-thalassemic daughter from the first pregnancy but the second pregnancy ended unexpectedly with Hb Bart's hydrops fetalis. Analysis of the archived DNA specimen of the husband demonstrated that he was in fact a carrier of the (-(THAI)) alpha(o)-thalassemia determinant. A successful application of a multiplex PCR for simultaneous detection of these two forms of alpha(o)-thalassemia in prenatal diagnosis at the third pregnancy was demonstrated and identified that the fetus was a carrier of the (-(SEA)) alpha(o)-thalassemia. CONCLUSION Although relatively rare, the (-(THAI)) alpha(o)-thalassemia should be included in a routine screening to prevent a Hb Bart's hydrops fetalis syndrome. A simple DNA assay based on a multiplex PCR approach would therefore provide an effective means for alpha(o)-thalassemia screening in the region.
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Deng J, Peng WL, Li J, Fang C, Liang XY, Zeng YH, Sun HY, Zhou CQ, Zhuang GL. Successful preimplantation genetic diagnosis for alpha- and beta-thalassemia in China. Prenat Diagn 2007; 26:1021-8. [PMID: 16986175 DOI: 10.1002/pd.1549] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
METHODS & RESULTS In southern China, the average carrier rates of alpha-thalassemia and beta-thalassemia in the population are as high as 10.3% and 2.8%, respectively. Because of the high rates, they are known as 'social diseases' in some regions. In this study, the fluorescent gap PCR, which can detect the alpha-thalassemia Southeast Asia deletion (SEA deletion), was applied in four clinical applications of preimplantation genetic diagnosis (PGD) on four couples, among whom both partners were alpha-thalassemia carriers. Two patients became pregnant and two healthy babies were born, which confirmed the PGD results. The single cell multiplex nested PCR followed by reverse dot blot (RDB), which can simultaneously detect the 16 beta-thalassemia mutations in the Chinese population, was applied in four clinical PGD cycles on four couples among whom both partners were beta-thalassemia carriers. One pregnancy was achieved and it resulted in a live healthy birth, which confirmed the results of PGD. The amplification efficiencies of the two protocols described above were 89.5% and 93.9%, respectively. The allele drop-out (ADO) rates of these two protocols were 5.9% and 10.9%, respectively. CONCLUSION These studies represent the successful applications of PGD protocols that can detect more than 95% of alpha- and beta -thalassemia mutations in the Chinese population.
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Affiliation(s)
- Jie Deng
- Reproductive Medical Center, 1st Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
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24
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Chen CP, Chang TY, Su YN, Hsu CY, Wang W. Prenatal two- and three-dimensional ultrasound diagnosis of limb reduction defects associated with homozygous alpha-thalassemia. Fetal Diagn Ther 2006; 21:374-9. [PMID: 16757914 DOI: 10.1159/000092468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Accepted: 09/05/2005] [Indexed: 11/19/2022]
Abstract
OBJECTIVES We present the prenatal two-dimensional (2D-) and three-dimensional ultrasound (3D-US) diagnosis of limb reduction defects associated with homozygous alpha-thalassemia and a review of the literature. METHODS At 17 weeks' gestation, amniocentesis was performed for cytogenetic and molecular studies, and 2D- and 3D-US examinations were made for evaluation of the fetal malformations. RESULTS Amniocentesis revealed a 46,XY karyotype and molecular analysis of the amniocytes showed that the fetus was homozygous for the Southeast Asian deletion (--SEA/--SEA). 2D-US examination revealed bilateral ventriculomegaly, brachycephaly, pleural effusion, digital deficiency and hypoplasia of the right foot, and digital deficiency of the left foot. 3D-US confirmed the distal limb reduction defects. CONCLUSIONS When the fetus is at risk for homozygous alpha-thalassemia, 2D- and 3D-US examinations are useful for prenatal detection of the associated limb reduction defects. Prenatal identification of the possible association with limb reduction defects is important for parental counseling and decision-making when intrauterine fetal therapy is an option.
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Affiliation(s)
- Chih-Ping Chen
- Department of Obstetrics and Gynecology, Mackay Memorial Hospital, and Institute of Clinical Nursing, School of Nursing, National Yang-Ming University, Taipei, Taiwan, ROC.
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Li DZ, Liao C, Li J, Xie XM, Huang YN, Wu QC. Hemoglobin H hydrops fetalis syndrome resulting from the association of the - -SEA deletion and the alphaQuong Szealpha mutation in a Chinese woman. Eur J Haematol 2005; 75:259-61. [PMID: 16104884 DOI: 10.1111/j.1600-0609.2005.00493.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A case with Hb H hydrops fetalis syndrome resulting from the association of the - -(SEA) deletion and the alpha(Quong Sze)alpha mutation is reported. This is the first description of Hb H hydrops associated with the Hb Quong Sze mutation.
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Affiliation(s)
- D Z Li
- Prenatal Diagnostic Center, Guangzhou Maternal & Neonatal Hospital, Guangzhou Medical College, Guangdong, China.
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26
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Chen CP, Su YN, Huang JP, Lin YH, Wang W. Asymmetrical terminal limb defects in a hydropic infant with homozygous ?-thalassemia-1. Prenat Diagn 2005; 25:178-9. [PMID: 15712377 DOI: 10.1002/pd.1092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wiwanitkit V. Overview of molecular deletion patterns of alpha0-thalassemia in Thailand. ACTA ACUST UNITED AC 2004; 10:122-3. [PMID: 15224771 DOI: 10.1532/lh96.03048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Leung KY, Lee CP, Tang MHY, Chan HY, Ma ESK, Chan V. Detection of increased middle cerebral artery peak systolic velocity in fetuses affected by hemoglobin H Quong Sze disease. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2004; 23:525-526. [PMID: 15133810 DOI: 10.1002/uog.1051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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29
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Tongsong T, Wanapirak C, Sirichotiyakul S, Chanprapaph P. Sonographic markers of hemoglobin Bart disease at midpregnancy. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2004; 23:49-55. [PMID: 14756353 DOI: 10.7863/jum.2004.23.1.49] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVE To evaluate the efficacy of various sonographic markers at midpregnancy in predicting fetal hemoglobin Bart disease. METHODS Four hundred eighty-eight pregnancies at risk of having fetuses with hemoglobin Bart disease were recruited for prenatal diagnosis with cordocentesis at 18 to 21 gestational weeks. Before cordocentesis, the sonographic markers, including cardiothoracic ratio, placental thickness, pericardial effusion, pleural effusion, ascites, subcutaneous edema, cord edema, dilated umbilical vein, and amniotic fluid index, were assessed and recorded. The definite fetal diagnosis was based on blood analysis. The efficacy of each sonographic marker in predicting hemoglobin Bart disease was evaluated by sensitivity and specificity. RESULTS Among 488 pregnancies undergoing prenatal diagnosis, 100 fetuses were proved to be affected by hemoglobin Bart disease. The cardiothoracic ratio gave the highest sensitivity, 95.0%, with specificity of 96.1%, followed by placental thickness. Signs of hydrops fetalis were observed in 33.0% of cases; they did not increase the sensitivity of the cardiothoracic ratio but strongly reinforced the diagnosis when they appeared. CONCLUSIONS At midpregnancy, sonographic markers can effectively differentiate normal pregnancies from those with fetal hemoglobin Bart disease. Among couples at risk with no sonographic markers, the risk of having an affected child is nearly eliminated. The most sensitive marker was the cardiothoracic ratio, followed by placental thickness.
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Affiliation(s)
- Theera Tongsong
- Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
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30
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Bhardwaj U, Zhang YH, Blackburn W, McCabe LL, McCabe ERB. Rapid confirmation of Southeast Asian and Filipino alpha-thalassemia genotypes from newborn screening specimens. Am J Hematol 2002; 71:56-8. [PMID: 12221678 DOI: 10.1002/ajh.10182] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Alpha(+)-thalassemia (-alpha) is prevalent throughout tropical and subtropical regions of world, whereas alpha(0)-thalassemia (--) occurs at higher frequency in Southeast Asia. Homozygosity for the alpha(0)-thalassemia deletion (--/--) is a serious health problem in Southeast Asia and the Philippines and is responsible for the majority of hydrops fetalis in this region. Asian immigration in United States has impacted the demography of genetic disease in U.S. As Asians comprise of 10% of all California births and represent a population at highest risk for alpha(0)-thalassemia, we developed a rapid and efficient PCR approach to detect the common alpha(0)-thalassemia deletions in Southeast Asians and Filipinos using newborn screening specimen.
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Affiliation(s)
- Urvashi Bhardwaj
- Department of Pediatrics, UCLA School of Medicine, Los Angeles, California 90095-1752, USA
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31
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Viprakasit V, Green S, Height S, Ayyub H, Higgs DR. Hb H hydrops fetalis syndrome associated with the interaction of two common determinants of alpha thalassaemia (--MED/(alpha)TSaudi(alpha)). Br J Haematol 2002; 117:759-62. [PMID: 12028055 DOI: 10.1046/j.1365-2141.2002.03427.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To date, more than 35 single or oligonucleotide mutations of the alpha genes that cause alpha thalassaemia have been described. Their interactions give rise to widely variable clinical manifestations, from a mild hypochromic, microcytic anaemia to a lethal intrauterine anaemia associated with hydrops fetalis. Understanding the molecular genetics enables accurate genotyping, genetic counselling and prenatal testing for the most severe forms of alpha thalassaemia. Here we show for the first time that the interaction between two relatively common forms of alpha thalassaemia (--MED/(alpha)TSaudi(alpha)) may be associated with a clinically severe form of alpha thalassaemia, Hb H hydrops fetalis.
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Affiliation(s)
- Vip Viprakasit
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
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McBride KL, Snow K, Kubik KS, Fairbanks VF, Hoyer JD, Fairweather RB, Chaffee S, Edwards WH. Hb Dartmouth [alpha66(E15)Leu-->Pro (alpha2) (CTG-->CCG)]: a novel alpha2-globin gene mutation associated with severe neonatal anemia when inherited in trans with Southeast Asian alpha-thalassemia-1. Hemoglobin 2001; 25:375-82. [PMID: 11791870 DOI: 10.1081/hem-100107874] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We report a novel mutation at alpha66(E15)Leu-->Pro (alpha2) (CTG-->CCG), that we have named Hb Dartmouth for the medical center at which the patients were cared for, in monozygotic twins who also inherited the Southeast Asian alpha-thalassemia-1 deletion. The mother, of Khmer ancestry, is heterozygous for alpha-thalassemia-1. The father, who is of Scottish-Irish ancestry, is a silent carrier of the codon 66 mutation. The twins had severe neonatal anemia requiring transfusion.
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Affiliation(s)
- K L McBride
- Department of Pediatrics and Adolescent Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA
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Sun CF, Lee CH, Cheng SW, Lin MH, Wu TL, Tsao KC, Chiu DT, Liou JD, Chu DC. Real-time quantitative PCR analysis for alpha-thalassemia-1 of Southeast Asian type deletion in Taiwan. Clin Genet 2001; 60:305-9. [PMID: 11683777 DOI: 10.1034/j.1399-0004.2001.600409.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Since homozygosity of the alpha-thalassemia-1 of Southeast Asian (SEA) type deletion results in hydrops fetalis, a novel protocol based on the real-time quantitating polymerase chain reaction (PCR) technique has been developed to quantify the intact and aberrant alpha-globin genes in adults. The ratio of the normal/SEA-bearing alpha-globin genes was expressed in cycle threshold (C(T)) values. Theoretically, a relative ratio of one to one was anticipated in individuals carrying the SEA type deletion. Twenty-five heterozygous and 20 normal cases were analyzed retrospectively with this protocol. Data showed that the CT values for the intact alpha-globin gene allele and the allele bearing the SEA type deletion in carriers were 28.74+/-1.49 and 26.46+/-2.05, respectively. Therefore, the ratio of normal/SEA type deletion-bearing alpha-globin genes in the carriers was 1.09+/-0.043. No ambiguous results were observed from other less common genotypes associated with alpha-thalassemia, such as the Philippine type deletion. Based on the results, we concluded that this protocol could provide a rapid method to mass screen carriers with alpha-thalassemia-1 of SEA type deletion in this region.
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Affiliation(s)
- C F Sun
- Department of Clinical Pathology, Chang Gung Memorial Hospital, Lin-Kou, Taiwan
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34
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Ma SK, Chan AY, Chiu EK, Chan LC. Haemoglobin H disease due to (--SEA) alpha-globin gene deletion and alpha2-codon 30 (DeltaGAG) mutation: a family study. CLINICAL AND LABORATORY HAEMATOLOGY 2001; 23:325-7. [PMID: 11703416 DOI: 10.1046/j.1365-2257.2001.00411.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A Chinese family in which two siblings suffer from haemogloblin (Hb) H disease due to (--SEA) alpha-globin gene deletion and alpha2-codon 30 (DeltaGAG) mutation is described. Both siblings are transfusion-independent and have survived to adulthood. In contrast to previous report of hydrops fetalis associated with zeta-alpha-thal-1 and alpha2-codon 30 (DeltaGAG) mutation, the zeta-globin genes are intact in the two siblings, which most probably alleviates the gamma-chain excess and protects the fetus from severe anaemia. Correlation of genotype with phenotype in Hb H disease is important for genetic counselling, especially in the antenatal setting.
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Affiliation(s)
- S K Ma
- Haematology Section, Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China.
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35
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Lorey F, Charoenkwan P, Witkowska HE, Lafferty J, Patterson M, Eng B, Waye JS, Finklestein JZ, Chui DH. Hb H hydrops foetalis syndrome: a case report and review of literature. Br J Haematol 2001; 115:72-8. [PMID: 11722414 DOI: 10.1046/j.1365-2141.2001.03080.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Haemoglobin H (Hb H) disease is caused by deletion or inactivation of three alpha-globin genes, leaving only one intact and active alpha-globin gene. People with Hb H disease usually have moderate anaemia, but are generally thought to be asymptomatic. Some Hb H disease patients require transfusions, and there are reports of fetuses with Hb H disease who have severe anaemia in utero resulting in fatal hydrops foetalis syndrome. We now report a case of Hb H hydrops foetalis syndrome, caused by the inheritance of a hitherto novel alpha-globin gene point mutation (codon 35 TCC-->CCC or Serine-->Proline) and an alpha-thalassaemia deletion of the Filipino type removing all zeta-alpha-globin genes on the other chromosome 16. The infant was delivered prematurely because of pericardial effusion and fetal distress, and was found to have severe anaemia and congenital anomalies. A review of the relevant literature on this syndrome is presented, and serves to underscore the phenotypic variations of Hb H disease and the need for surveillance for this condition among newborns and genetic counselling in communities with a high proportion of at-risk populations.
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Affiliation(s)
- F Lorey
- Genetic Disease Branch, California Department of Health Services, Berkeley, CA, USA
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36
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Piyamongkol W, Harper JC, Delhanty JD, Wells D. Preimplantation genetic diagnostic protocols for alpha- and beta-thalassaemias using multiplex fluorescent PCR. Prenat Diagn 2001; 21:753-9. [PMID: 11559912 DOI: 10.1002/pd.170] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Haemoglobinopathies including alpha- and beta-thalassaemia are the world's most common class of single gene disorder. Prenatal diagnosis (PND) for beta-thalassaemia has been proven to be an effective strategy for controlling the incidence of new cases and is widely used in several countries where the disease is common. Successful preimplantation genetic diagnosis (PGD) protocols for beta-thalassaemia have been introduced using restriction fragment length polymorphism (RFLP), single-stranded conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE). However, contamination and allele dropout (ADO) remain an important concern for all of these strategies. In the present study two PGD protocols for detecting beta-thalassaemia mutations (codon 41-42 and IVSI-110) and one for alpha-thalassaemia (SEA mutation) have been designed and tested. These methods contain failsafe mechanisms to reduce the risk of misdiagnosis due to ADO or contamination and utilise multiplex fluorescent PCR (F-PCR). Interestingly, amplification efficiency and ADO were significantly affected by the choice of DNA polymerase and the freshness of the single cells used. The close similarity between the DNA sequences of beta-globin and delta-globin was also found to be an important issue that necessitated careful design of primers for the beta-globin gene.
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Affiliation(s)
- W Piyamongkol
- UCL Centre for Preimplantation Genetic Diagnosis, Department of Obstetrics & Gynaecology, University College London, London, UK
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Abstract
OBJECTIVE Thalassemia is a highly prevalent genetic disorder in Taiwan. The major goal of this study was to present a feasible protocol for the prenatal diagnosis of thalassemia. METHOD Prenatal investigation of thalassemia was performed on 57 at-risk cases at the Mackay Memorial Hospital, Taipei, Taiwan. We developed a method using polymerase chain reaction (PCR) and high-throughput DNA sequencing to detect mutations. All diagnoses were confirmed after delivery. RESULT Prenatal testing revealed 16 normal fetuses, 24 alpha-thal-1 carriers, eight Hb Bart's hydrops fetalis, seven beta-thalassemia minor, and two beta-thalassemia major fetuses. No false-positive or false-negative cases were found during the postnatal follow-ups. CONCLUSION The results of this study indicate that prenatal diagnosis of thalassemia syndromes in Taiwan is successful with the use of a rapid and accurate molecular method.
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Affiliation(s)
- S R Chern
- Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan
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Chu DC, Lee CH, Lo MD, Cheng SW, Chen DP, Wu TL, Tsao KC, Chiu DT, Sun CF. Non-radioactive southern hybridization for early diagnosis of ?-thalassemia with Southeast Asian-type deletion in Taiwan. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/1096-8628(20001211)95:4<332::aid-ajmg7>3.0.co;2-o] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Chan V, Yam I, Chen FE, Chan TK. A reverse dot-blot method for rapid detection of non-deletion alpha thalassaemia. Br J Haematol 1999; 104:513-5. [PMID: 10086788 DOI: 10.1046/j.1365-2141.1999.01221.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A reverse dot blot method based on membrane-bound allele-specific oligonucleotides as hybridization targets for amplified alpha-gene fragments has been developed for the rapid detection of four non-deletion alpha thalassaemia defects found in the Chinese. Since these non-deletion defects account for 22 8% of haemoglobin H disease, a sensitive, specific and rapid screening method should be of value.
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Affiliation(s)
- V Chan
- University Department of Medicine, Queen Mary Hospital, Hong Kong.
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41
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Ko TM, Tseng LH, Kao CH, Lin YW, Hwa HL, Hsu PM, Li SF, Chuang SM. Molecular characterization and PCR diagnosis of Thailand deletion of alpha-globin gene cluster. Am J Hematol 1998; 57:124-30. [PMID: 9462544 DOI: 10.1002/(sici)1096-8652(199802)57:2<124::aid-ajh6>3.0.co;2-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Thailand deletion of alpha-Thalassemia (thal) 1 involves the zeta2-, phi zeta1-, alpha2-, alpha1-, and theta1-globin genes. In Southeast Asians and Taiwanese, this mutation is the second most common long-segment deletion of two alpha-globin genes, after the Southeast Asian deletion. To define the Thailand deletion breakpoints, we used polymerase chain reaction (PCR) to amplify the normal-sequence DNA fragments across the breakpoints. The amplified products were sequenced directly or after cloning into pGem-3Z or pCR2.1 vectors. Comparison of the normal and mutant sequences revealed that the 5' breakpoint lies between nucleotides 1,269 and 1,290 upstream of the initiator codon adenine of the zeta2-globin gene, and the 3' breakpoint lies between nucleotides 29,387 and 29,408 downstream of it. A total of 30,677 nucleotides were deleted. Both breakpoints mentioned above lie within the Alu repetitive sequences and an extensive sequence homology is present around the two breakpoints. These findings suggest that homologous recombination is the mechanism by which the deletion occurs. Based on our data, we used three oligonucleotide primers to amplify the regions across the deletion and its corresponding normal sequence. The feasibility of PCR diagnosis was confirmed in 20 carriers with this deletion.
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Affiliation(s)
- T M Ko
- Department of Obstetrics and Gynecology, College of Medicine, National Taiwan University, Taipei.
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46
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KO TSANGMING, TSENG LIHUI, HWA HSIAOLIN, HSU PIMEI, LI SHWUFAN, CHU JOYU, LU PEIJEN, LEE TZUYAO, CHUANG SOUMING. MISDIAGNOSIS OF HOMOZYGOUS ALPHA-THALASSAEMIA 1 MAY OCCUR IF POLYMERASE CHAIN REACTION ALONE IS USED IN PRENATAL DIAGNOSIS. Prenat Diagn 1997. [DOI: 10.1002/(sici)1097-0223(199706)17:6<505::aid-pd104>3.0.co;2-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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47
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Chan AY, So CK, Chan LC. Comparison of the HbH inclusion test and a PCR test in routine screening for alpha thalassaemia in Hong Kong. J Clin Pathol 1996; 49:411-3. [PMID: 8707958 PMCID: PMC500483 DOI: 10.1136/jcp.49.5.411] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
AIM To compare the haemoglobin (Hb) H inclusion test with a polymerase chain reaction (PCR) test in routine screening for alpha thalassaemia. METHODS Ninety nine peripheral blood samples from Chinese patients with mean corpuscular volume below 80 fl were screened for alpha thalassaemia using the HbH inclusion test and by PCR utilising primers bridging the common deletion breakpoint of the South East Asian (--SEA/) deletion. RESULTS The HbH inclusion test was positive in 78 (79%) patients, 73 (93.7%) of whom carried the (--SEA/) deletion on analysis of their DNA by PCR, as did one patient with a negative HbH inclusion test. CONCLUSIONS These results suggest that in areas with a high prevalence of the (--SEA/) deletion, such as Hong Kong, the HbH inclusion test can be replaced by PCR as the investigation of choice in screening for alpha thalassaemia.
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Affiliation(s)
- A Y Chan
- Department of Pathology, University of Hong Kong
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48
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Abstract
The technology has been available to detect carriers of haemoglobin disorders since the late 1960s. Prenatal diagnosis has been available since 1978. First trimester diagnosis by chorionic villus sampling and DNA analysis was introduced in 1982, and subsequent simplifications in DNA technology have made screening, counselling and prenatal diagnosis cost-effective at the community level, in countries at all levels of development. Audit of prenatal diagnosis for haemoglobin disorders in countries which have the resources and infrastructure necessary for genetic population screening (such as the UK and other European countries), has shown that the number of prenatal diagnoses actually performed fall far short of expectation. The demonstration that this reflects failures in delivering information, screening and counselling to the populations at risk, rather than rejection of prenatal diagnosis, shows the importance of placing more emphasis on the organisational and social requirements for genetic population screening. In some countries current attitudes towards abortion exclude provision of prenatal diagnosis within the health service, but in many such cases it has been set up in the private sector. It is also being introduced through combined private and charitable efforts in an increasing number of developing countries, including some with extremely limited health resources: such centres are likely to act as nuclei for emergence of genetics services in these communities. A particularly notable recent achievement is the introduction of prenatal diagnosis in Nigeria, where 1-2% of all children born suffer from sickling disorders.
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Affiliation(s)
- M Petrou
- Department of Obstetrics and Gynaecology, UCL Medical School, London, U.K
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49
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Abstract
Hematologic disorders are implicated in approximately 10% to 27% of cases of nonimmune hydrops fetalis. In almost all of these disorders, anemia leading to heart failure, edema, ascites, and anasarca is the final common denominator. The etiology of the anemia in these cases can be conveniently divided into two categories: (1) excessive erythrocyte loss by hemolysis or hemorrhage, and (2) erythrocyte underproduction. The former include intrinsic erythrocyte abnormalities such as alpha-thalassemia and glucose-6-phosphate dehydrogenase deficiency, and conditions with excessive fetal blood loss such as fetomaternal hemorrhage and twin-twin transfusion. The latter include bone marrow replacement syndromes and conditions associated with failure of erythrocyte production. The presentation, diagnosis, and management of hematologic disorders associated with nonimmune hydrops fetalis are reviewed.
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Affiliation(s)
- M O Arcasoy
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
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Hall GW, Thein SL, Newland AC, Chisholm M, Traeger-Synodinos J, Kanavakis E, Kattamis C, Higgs DR. A base substitution (T-->C) in codon 29 of the alpha 2-globin gene causes alpha thalassaemia. Br J Haematol 1993; 85:546-52. [PMID: 8136277 DOI: 10.1111/j.1365-2141.1993.tb03346.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have identified three individuals of Greek or Greek Cypriot origin with an atypical form of HbH disease characterized by a severe hypochromic microcytic anaemia associated with relatively small amounts of HbH in the peripheral blood. Molecular analysis has shown that each is a compound heterozygote for a previously described mutation affecting the poly A addition signal (AATAAA-->AATAAG) and a previously undescribed mutation involving a T-->C transition in codon 29 of the alpha 2 gene causing a leucine-->proline substitution. Although this mutation would be expected to produce an unstable haemoglobin and hence a haemolytic anaemia, simple heterozygotes for the alpha 29Leu-->Pro mutation have the phenotype of alpha-thalassaemia trait.
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Affiliation(s)
- G W Hall
- MRC Molecular Haematology Unit, John Radcliffe Hospital, Oxford
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