Beta-thalassemia

General Information (adopted from Orphanet):

Synonyms, Signs:
Number of Symptoms 21
OrphanetNr: 848
OMIM Id: 613985
ICD-10: D56.1
UMLs: C0005283
MeSH: D017086
MedDRA: 10043391
Snomed: 65959000
79592006

Prevalence, inheritance and age of onset:

Prevalence: 0.5 of 100 000 [Orphanet]
Inheritance: Autosomal recessive
[Orphanet]
Age of onset: Infancy
Childhood
[Orphanet]

Disease classification (adopted from Orphanet):

Parent Diseases: Beta-thalassemia and related diseases
 -Rare genetic disease
 -Rare hematologic disease
Hematological disorder with renal involvement
 -Rare genetic disease
 -Rare renal disease
Pituitary hormone deficiency secondary to storage disease
 -Rare endocrine disease
 -Rare genetic disease

Symptom Information: Sort by abundance 

1
(HPO:0000929) Abnormality of the skull Frequent [Orphanet] 53 / 7739
2
(HPO:0100851) Abnormal emotion/affect behavior Frequent [Orphanet] 85 / 7739
3
(HPO:0008373) Puberty and gonadal disorders Frequent [Orphanet] 156 / 7739
4
(HPO:0000924) Abnormality of the skeletal system Very frequent [Orphanet] 114 / 7739
5
(HPO:0004349) Reduced bone mineral density Frequent [Orphanet] 165 / 7739
6
(HPO:0002240) Hepatomegaly Frequent [Orphanet] 467 / 7739
7
(HPO:0012437) Abnormal gallbladder morphology Occasional [Orphanet] 17 / 7739
8
(HPO:0001744) Splenomegaly Very frequent [Orphanet] 337 / 7739
9
(HPO:0001396) Cholestasis Occasional [Orphanet] 136 / 7739
10
(HPO:0200042) Skin ulcer Occasional [Orphanet] 138 / 7739
11
(HPO:0000980) Pallor Very frequent [Orphanet] 52 / 7739
12
(HPO:0001638) Cardiomyopathy Occasional [Orphanet] 192 / 7739
13
(HPO:0001873) Thrombocytopenia Occasional [Orphanet] 224 / 7739
14
(HPO:0001935) Microcytic anemia Very frequent [Orphanet] 32 / 7739
15
(HPO:0004936) Venous thrombosis Occasional [Orphanet] 41 / 7739
16
(HPO:0011902) Abnormal hemoglobin Very frequent [Orphanet] 18 / 7739
17
(HPO:0001903) Anemia Very frequent [Orphanet] 289 / 7739
18
(HPO:0011031) Abnormality of iron homeostasis Frequent [Orphanet] 16 / 7739
19
(HPO:0001945) Fever Frequent [Orphanet] 218 / 7739
20
(HPO:0002093) Respiratory insufficiency Frequent [Orphanet] 410 / 7739
21
(HPO:0001324) Muscle weakness Frequent [Orphanet] 859 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Description: (OMIM) Beta-thalassemia is characterized by a reduced production of hemoglobin A (HbA, alpha-2/beta-2), which results from the reduced synthesis of beta-globin chains relative to alpha-globin chains, thus causing an imbalance in globin chain production and hence abnormal erythropoiesis. The ...
Diagnosis OMIM - Prenatal Diagnosis

By means of a simplified method for trophoblast biopsy together with restriction endonuclease analysis of fetal DNA, Old et al. (1982) made first-trimester prenatal diagnosis in the case of 3 fetuses at risk ...

Clinical Description OMIM Patients with thalassemia major present in the first year of life with severe anemia; they are unable to maintain a hemoglobin level about 5 gm/dl. Clinical details of this disorder have been detailed extensively in numerous monographs and ...
Molecular genetics OMIM For a review of mutations in the HBB gene and the beta-globin gene cluster causing beta-thalassemia, see 141900.

Uda et al. (2008) found that the C allele of dbSNP rs11886868 in the BCL11A gene (606557) was ...

Population genetics OMIM Beta-thalassemia is one of the most common autosomal recessive disorders worldwide. It is highly prevalent in populations in the Mediterranean, Middle East, Transcaucasus, Central Asia, Indian subcontinent, and Far East. It is also relatively common in populations of ...
Diagnosis GeneReviews Thalassemia major is suspected in an infant or child younger than age two years with severe microcytic anemia, mild jaundice, and hepatosplenomegaly. Untreated, affected children usually manifest failure to thrive and expansion of the bone marrow to compensate for ineffective erythropoiesis. ...
Clinical Description GeneReviews The phenotypes of the homozygous β-thalassemias include thalassemia major and thalassemia intermedia. The clinical severity of the β-thalassemia syndromes depends on the extent of alpha globin chain/non-alpha globin chain (i.e., β+ γ) imbalance. The non-assembled alpha globin chains that result from unbalanced alpha globin chain/non-alpha globin chain synthesis precipitate in the form of inclusions. These alpha globin chain inclusions damage the erythroid precursors in the bone marrow and in the spleen, causing ineffective erythropoiesis. Individuals with thalassemia major usually come to medical attention within the first two years of life; they subsequently require regular red blood cell transfusions to survive. Those who present later and rarely require transfusion are said to have thalassemia intermedia....
Genotype-Phenotype Correlations GeneReviews Any inherited or acquired condition that reduces the alpha/non-alpha globin chain imbalance in β-thalassemia results in a lesser degree of alpha globin chain precipitation and leads to a mild β-thalassemia phenotype ...
Differential Diagnosis GeneReviews β-thalassemia associated with other features. In rare instances the β-thalassemia defect does not lie in HBB or in the β-globin gene cluster. In instances in which the β-thalassemia trait is associated with other features, the molecular lesion has been found either in the gene encoding the transcription factor TFIIH (β-thalassemia trait associated with xeroderma pigmentosum and tricothiodystrophy) or in the X-linked transcription factor GATA-1 (X-linked thrombocytopenia with thalassemia) (see GATA1-Related Cytopenia) [Viprakasit et al 2001, Freson et al 2002]. ...
Management GeneReviews The initial step following diagnosis of β-thalassemia in an individual is to distinguish thalassemia intermedia from thalassemia major (see Testing Strategy). The diagnosis of thalassemia major implies the need for a regular transfusion program; the diagnosis of thalassemia intermedia implies the need for intermittent transfusions on an as-needed basis....
Molecular genetics GeneReviews Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED....