Thalassaemia is carried by 150 million or 3% of the world population. It is clinically apparent in 15 million people. It is particularly associated with people of Mediterranean origin, Arabs, and Asians. Certain types of thalassaemia are more common in specific parts of the world.
Alpha thalassaemia is common in those parts of the world where malaria is endemic.
Beta thalassaemia is much more common in Mediterranean countries such as Greece, Italy, and Spain. Many Mediterranean islands, including Cyprus, Sardinia, and Malta, have a significantly high incidence of severe beta thalassaemia, constituting a major public health problem. For instance, in Cyprus, 1 in 7 individuals carries the gene, which translates into 1 in 49 marriages between carriers and 1 in 158 newborns expected to have beta thalassaemia major.
Beta thalassaemia is also common in North Africa, the Middle East, India, and Eastern Europe. On the other hand, alpha thalassaemia is more common in Southeast Asia, India, the Middle East, and Africa.
The carrier rates for thalassaemia are:
- 1 in 7 Cypriots
- 1 in 12 Greeks
- 1 in 10 Gujeratis
- 1 in 10 Sindhis
- 1 in 20 South Indians
- 1 in 25 Pakistanis
- 1 in 15 to 1 in 30 Punjabis and Bangladeshis
In Malaysia, thalassaemia is a public health problem among the Malays and Chinese where Indians form only a small percentage of those with thalassaemia.
- Hb E and β thalassaemia are the most common inherited hematologic disorders. The carrier rate for beta thalassaemia is around 3 to 5 percent.
- Estimated number of beta-thalassaemia carriers is 60,000.
- Estimated number of beta-thalassemia major and HbE beta-thalassemia are 5000.
- There is also an estimated 120 to 240 new cases of beta thalassaemia major each year and about 61 with Hb Barts hydrops fetalis.
In 1995, about 40% of Hb E beta thalassaemia and beta thalassaemia were dependent on regular blood transfusions for survival. Since there is no national screening policy, national Thalassaemia trait (carrier) registry or registry of beta Thalassaemia major patients, the current figures available are presumptive, derived from population studies data of various research workers in the country. Based on an estimated population of 22.7 million, the number of cases afflicted with beta Thalassaemia major is 2140 among Malays and 2240 among Chinese. Sabah appears to have a higher incidence of Thalassaemia major, with 676 cases registered with the Thalassaemia Association of Sabah.
For alpha thalassaemia, a study done by University of Malaya in 2005 on 650 pregnant women shows that
- 15.8% of the pregnant women were confirmed as α-thalassaemia carriers.
- The double Southeast Asian (--SEA) double alpha-globin gene deletion was significantly higher in the Chinese (15%) compared to the Malays (2.5%) and not detected in the Indians studied.
http://www.moh.gov.my/MohPortal/DownloadServlet?id=727&type=2
http://www.medic.upm.edu.my/FPSK/Penyelidikan/
http://www3.interscience.wiley.com/journal/118666291/abstract?CRETRY=1&SRETRY=0
http://www.patient.co.uk/showdoc/40001022/
http://emedicine.medscape.com/article/958850-overview
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