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Diagnosis of thalassemia and hemoglobinopathies requires a comprehensive evaluation combining red blood cell phenotypes, hemoglobin profiles, and DNA analysis.
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A recent classification of thalassemia syndrome is based on the patients’ clinical severity that is their transfusion requirement, not genotypes.
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Hemoglobin analysis can be performed at any age; however, interpretation requires age-specific reference ranges.
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Genetic analysis for globin mutations are required to confirm the clinical
Clinical Classification, Screening and Diagnosis for Thalassemia
Section snippets
Key points
Clinical classification of thalassemia
Disorders of hemoglobin (Hb) are characterized according to pathologic defects on globin chain production; a quantitative defect or “thalassemia,” mainly α-thalassemia and β-thalassemia, and a qualitative defect, namely hemoglobinopathy (or structural Hb variants), and, last, hereditary persistence of fetal Hb. Interactions of these 3 types of globin defects result in a wide array of thalassemia syndromes and related diseases.1
Thalassemia has a wide spectrum of clinical severity, which was
Screening and diagnosis of thalassemia
In general, the screening and diagnostic algorithm for thalassemia can be divided into 2 levels—population and individual—in which different approaches have been implemented owing to different objectives of screening. The screening methods used in a population approach that focused on identification of thalassemia and Hb variant traits are described. Last, comprehensive diagnostic tests for thalassemia confirmation are discussed. All currently available laboratory tests for screening and
Summary
Thalassemia diseases are classified into TDT and NTDT, based on patients’ clinical severity whether they require regular blood transfusions to survive (TDT) or not (NTDT). Screening and definitive diagnoses of thalassemia and hemoglobinopathies require a comprehensive evaluation, from clinical history, physical examination, and laboratory results, including a complete blood count, Hb profiles, and molecular studies. There are several screening tools used in population screening. Clinicians need
References (78)
- et al.
Overview on practices in thalassemia intermedia management aiming for lowering complication rates across a region of endemicity: the OPTIMAL CARE study
Blood
(2010) - et al.
Recent advances and treatment challenges in patients with non-transfusion-dependent thalassemia
Blood Rev
(2012) - et al.
An international registry of survivors with Hb Bart's hydrops fetalis syndrome
Blood
(2017) - et al.
Hydrops fetalis due to an unusual form of Hb H disease
Blood
(1985) The definition and epidemiology of non-transfusion-dependent thalassemia
Blood Rev
(2012)- et al.
Splenectomy and thrombosis: the case of thalassemia intermedia
J Thromb Haemost
(2010) Haemoglobinopathy diagnosis: algorithms, lessons and pitfalls
Blood Rev
(2011)- et al.
Comparison of the accuracy of dichlorophenolindophenol (DCIP), modified DCIP, and hemoglobin E tests to screen for the HbE trait in pregnant women
Int J Gynaecol Obstet
(2009) - et al.
Phenotypic effect of heterozygous alpha and beta 0-thalassemia interaction
Blood
(1983) - et al.
Screening for hemoglobin E trait in pregnant women
Int J Gynaecol Obstet
(2004)
Thalassaemia screening and confirmation of carriers in parents
Best Pract Res Clin Obstet Gynaecol
Phenotypic expression of hemoglobins A(2), E and F in various hemoglobin E related disorders
Blood Cells Mol Dis
A rapid and reliable 7-deletion multiplex polymerase chain reaction assay for alpha-thalassemia
Blood
Reverse dot-blot detection of the African-American beta-thalassemia mutations
Blood
Molecular assay of -alpha(3.7) and -alpha(4.2) deletions causing alpha-thalassemia by denaturing high-performance liquid chromatography
Clin Biochem
Molecular analysis of unknown beta-globin gene mutations using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique and its application in Thai families with beta-thalassemias and beta-globin variants
Clin Biochem
Detection of germline rearrangements in patients with alpha- and beta-thalassemia using high resolution array CGH
Blood Cells Mol Dis
Evaluation of alpha hemoglobin stabilizing protein (AHSP) as a genetic modifier in patients with beta thalassemia
Blood
The thalassaemia syndromes
Guidelines for the clinical management of thalassaemia
Alpha thalassemia syndromes: from clinical and molecular diagnosis to bedside management
EHA Hematol Educ Program
Molecular defects in Hb H hydrops fetalis
Br J Haematol
Hb H Hydrops Fetalis Syndrome Caused by Association of the - -(SEA) Deletion and Hb Constant Spring (HBA2: c.427T > C) Mutation in a Chinese Family
Hemoglobin
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
Phenotypic variability in a Chinese family with nondeletional Hb H-Hb Quong Sze disease
Hemoglobin
Hb H hydrops foetalis syndrome: a case report and review of literature
Br J Haematol
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
Hb H hydrops fetalis syndrome associated with the interaction of two common determinants of alpha thalassaemia (–MED/(alpha)TSaudi(alpha))
Br J Haematol
alpha-Thalassemia with Haemoglobin Adana mutation: prenatal diagnosis
Malays J Pathol
Genetic basis, pathophysiology and diagnosis [Chapter 1]
Partial splenectomy in homozygous beta thalassaemia
Arch Dis Child
When to consider transfusion therapy for patients with non-transfusion-dependent thalassaemia
Vox Sang
Optimal management of beta thalassaemia intermedia
Br J Haematol
Identification and key management of non-transfusion-dependent thalassaemia patients: not a rare but potentially under-recognised condition
Orphanet J Rare Dis
A simplified screening strategy for thalassaemia and haemoglobin E in rural communities in south-east Asia
Bull World Health Organ
Screening for microcytemia in Italy: analysis of data collected in the past 30 years
Am J Hum Genet
State of the art and new developments in molecular diagnostics for hemoglobinopathies in multiethnic societies
Int J Lab Hematol
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Disclosure Statement: All authors have nothing to declare.