Download HUWEL LIFESCIENCES PVT. LTD. BETA THALESSEMIA Disease

HUWEL LIFESCIENCES PVT. LTD.
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BETA THALESSEMIA
Disease overview: Beta thalassemias (β thalassemias) are a group of inherited blood disorders. They are
caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes
ranging from severe anemia to clinically asymptomatic individuals. Global annual incidence is estimated at 1
in 100,000. It is an autosomal recessive disorder caused majorly by mutations and mRNA assembly.
Two major groups of mutations can be distinguished:
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Non-deletion forms: These defects, in general, involve a single base substitution or small deletion or inserts
near or upstream of the β globin gene. Most often, mutations occur in the promoter regions preceding the
beta-globin genes. Less often, abnormal splice variants are believed to contribute to the disease.
Deletion forms: Deletions of different sizes involving the β globin gene produce different syndromes such as
(βo) or hereditary persistence of fetal hemoglobin syndromes.
β thalassemias are most commonly observed in individuals from southern Europe, northern Africa and
India. It is usually associated with populations in which malaria was endemic historically.
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Mutations analyzed in this assay
1 FS 8/9 (+G)
2 Codon 15 (G>A)
3 Codon 30 (G>A)
4 IVS1-1 (G>T)
5 IVS1-5 (G>C)
6 FS 41/42 (-CTTT)
Symptoms: Mostly in thalassemia major and intermedia spleen is often enlarged and frequently removed
and gallstones are found. Beta thalassemia major usually present within the first two years of life with
severe anemia, poor growth and skeletal abnormalities during infancy. Untreated thalassemia major
eventually leads to death, usually by heart failure; therefore, birth screening is very important. Severe
symptoms include liver cirrhosis, liver fibrosis and in extreme cases, liver cancer. Heart failure, growth
impairment, diabetes osteoporosis is reported. Increased gastrointestinal iron absorption is seen in all
grades of beta thalassemia and increased red blood cell destruction by the spleen due to
ineffective erythropoiesis.
Preferred sample: BLOOD-EDTA
Transport: To be transported at 4 degrees
Methodology: Genomic DNA was isolated from Buffy coat cells of EDTA-Blood samples. PCR amplification
was carried out using specific primers designed for Beta globin gene. The resultant product was gel eluted
and sequenced.
Limitations: Rare diagnostic errors can occur due to primer site mutations. Beta globin gene mutations, will
not be detected.
Note: Although all precautions are taken and the results cross checked during DNA tests, the currently
available data indicates that the technical error rate for all such analysis is approx. 1-2%. The results assume
that all the information regarding the patient and the sample are correct and should be interpreted and
acted upon in the light of information noted above.
HUWEL LIFESCIENCES PVT. LTD.
Thriving on Science
References:
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ARUP Laboratories: http://www.aruplab.com
CDC: www.cdc.gov
NIH: www.nih.gov
Mayo clinic: www.mayoclinic.org
Other journals, articles and websites