Call for increased awareness of thalassemia

August 17, 2009

Courtesy by: theasiannews.co.uk

Despite thalassaemia mainly affecting those of Asian heritage, the vast majority of British Asians admit they have never heard of the potentially fatal genetic blood disorder.

New research shows that nearly two-thirds (63 per cent) have either never heard of the disease or know little about it.
Ignorance is particularly prevalent in the young, with more than seven-in-ten unaware of the disease.

According to the survey, supported by the UK Thalassaemia Society (UKTS), of those who had heard of the condition only half knew that the severe form can be fatal. While carriers of beta thalassaemia are normally healthy, a fifth of survey respondents also admitted there was a stigma attached to being diagnosed with thalassaemia among the Asian community – with a third of people admitting they would hide the fact that they suffered from the disorder and only 55 per cent saying they would tell their family about their condition.

Thalassaemia refers to a group of genetic blood disorders that affect the body’s production of haemoglobin, the oxygen-carrying component of red blood cells. The most severe form of the condition, beta thalassaemia major, can be fatal. Those affected – and there are currently over 700 sufferers in the UK – do not produce enough healthy mature red blood cells, which are vital in carrying oxygen around the body.

If a man and woman who are both carriers have children together, there is a 25 per cent chance with each pregnancy that the baby will be born beta thalassaemia major. An early symptom of this most severe form of thalassaemia is acute anaemia before the age of one.
Those affected then need regular transfusions plus constant medication and monitoring throughout their life to prevent dying from their condition.

Commenting on the research findings, Elaine Miller of the UK Thalassaemia Society said: “It is really quite shocking that awareness of the condition remains so low amongst those most vulnerable to the disorder. We urgently need to address this issue and de-stigmatise Thalassaemia amongst British Asians.”

On learning about the disease, over 90 per cent of respondents called for increased awareness of the condition.

Approximately 214,000 people in the UK carry the gene that passes the condition through the generations, and 79 per cent of sufferers have parents of Indian, Pakistani or Bangladeshi origin – the UKTS are committed to encouraging these groups to visit their GP in order to be tested for the thalassaemia gene.

The All Party Parliamentary Group summer reception for thalassaemia and sickle cell took place on Tuesday (14 July) to highlight the efforts of the UKTS in bringing thalassaemia to the forefront of political activity.
For more information visit http://www.ukts.org


New genetic target for sickle cell disease therapy

March 17, 2009

Courtesy by: huliq.com

Researchers have identified a gene that directly affects the production of a form of hemoglobin that is instrumental in modifying the severity of the inherited blood disorders sickle cell disease and thalassemia.

The discovery could lead to breakthrough therapies for sickle cell disease and thalassemia, which could potentially eliminate the devastating and life-threatening complications of these diseases, such as severe pain, damage to the eyes and other organs, infections, and stroke.

“Human Fetal Hemoglobin Expression is Regulated by the Developmental Stage-Specific Repressor BCL11A,” is published online in Science December 4. The study was conducted by researchers at Children’s Hospital Boston and Dana-Farber Cancer Institute and supported by the National Institutes of Health’s National Heart, Lung, and Blood Institute (NHLBI) and National Institutes of Diabetes and Digestive and Kidney Diseases, and by the Howard Hughes Medical Institute. Read Gene therapy corrects sickle cell disease in laboratory study

Hemoglobin is the protein in red blood cells that carries oxygen to the body’s tissues. In sickle cell disease, hemoglobin is abnormal and sticks together. The red blood cells become stiff and sickle-shaped, causing them to block blood vessels and rob tissues of necessary blood and oxygen. In thalassemia, the body has trouble producing adult forms of hemoglobin.

Other studies have shown that in patients with sickle cell disease, those who continue to produce fetal hemoglobin (HbF) have much milder forms of sickle cell anemia. For years, scientists have sought ways to increase HbF production in patients with sickle cell disease and thalassemia.

Researchers report that by suppressing a gene called BCL11A, HbF production improves dramatically. Their findings provide new insights into the mechanisms involved in the body’s switch from producing fetal hemoglobin to adult hemoglobin and identify a potential new target for therapies that could dramatically alter the course of sickle cell anemia and thalassemia.

The researchers built upon their recently reported results of genome-wide association studies that identified several gene variants associated with HbF levels. BCL11A was found to have the greatest effect on HbF levels. In the follow-up study reported today, they report that BCL11A encodes a transcription factor that directly suppresses HbF production.

A drug therapy that increases HbF levels enough to modify the severity of sickle cell disease is currently available. The drug hydroxyurea was approved by the FDA in 1998 to prevent pain crises in adults with sickle cell disease after studies showed that it increases fetal hemoglobin production, reduces the damaging effects of sickle cell disease, and improves some aspects of quality of life. Use of hydroxyurea is limited, however, in part because not all patients respond to the drug, and there are short-term and long-term adverse effects. New therapies targeting BCL11A would be the first to directly affect the natural processes involved in increasing HbF.

Sickle cell disease is the most common inherited blood disorder. In the United States, it affects approximately 70,000 people, primarily African Americans. Worldwide, sickle cell anemia affects millions of people and is found in people whose families come from Africa, South or Central America (especially Panama), Caribbean islands, Mediterranean countries, India, and Saudi Arabia.

The pain and complications associated with sickle cell disease can have a profound impact on patients’ quality of life, ability to work, and long-term health and well-being. In addition, people with sickle cell disease have a shortened life expectancy due to infections, lung problems, and stroke.

Treatments developed over the past three decades have led to the doubling of the life expectancy of sickle cell disease patients between 1972 and 2002. These treatments include medications, blood and bone marrow transfusions, and other procedures to relieve or prevent complications. Until now, however, scientists could not directly target processes known to affect the severity of sickle cell disease.-NIH/National Heart, Lung and Blood Institute


Gene test hope

March 16, 2009

BLOOD taken from a pregnant woman may reveal if her baby has a wide range of genetic diseases, researchers said.

A Chinese University of Hong Kong team said the technique could identify cystic fibrosis, beta-thalassemia and sickle cell disease.

The only checks currently available carry a high risk of miscarriage.

The test works by checking foetal DNA in the mother’s blood against her own, the Proceedings of the National Academy of Sciences reported. An estimated one in 25 people in the UK carries one copy of the gene for cystic fibrosis, but only people who have two bad copies will actually develop the disease. If both parents carry a single disease gene, there is a 25% chance a child they produce will inherit both, and become ill.

The discovery that DNA from the unborn child can be found in the mother’s plasma – part of blood – has opened new possibilities for testing.


Yale Researchers Find New Way to Fix Faulty Genes Sickle Cell Anemia, Other Inherited Diseases Targeted

March 14, 2009

Courtesy by: HealthNewsDigest.com

(HealthNewsDigest.com) – New Haven, Conn. – Yale University researchers have found a new method to create lasting genetic changes within human cells, opening up the possibility of new treatments for inherited diseases like sickle cell anemia.

The researchers corrected a specific defect within a human gene that causes the blood disorder thalassemia, researchers reported in a study to be published online in the journal Proceedings of the National Academy of Sciences USA. The disease affects production of hemoglobin, the molecule in red blood cells that carries oxygen to the body.

Scientists in the laboratory of Peter Glazer, professor and chair of the Department of Therapeutic Radiology and professor of genetics at the Yale School of Medicine were also able to slip a sort of genetic repair kit into blood stem cells. In theory, repairs to these hematopoietic progenitor cells would enable the body to produce healthy red blood cells indefinitely.

Genetic diseases like thalassemia and sickle cell anemia are particularly problematic to treat because defects are carried within DNA of every cell in the body. Glazer’s laboratory team, headed by Joanna Chin, created a series of artificial DNA molecules designed to bind to specific locations in the genome. These molecules, called triplex-forming oligonucleotides, trigger the DNA’s own repair system, resulting in potentially permanent correction of genetic defects.

In the past, gene-based therapies have met with limited successes in part because of difficulties finding ways to insert a new version of an entire gene into human cells and to have that new gene stay active for a long time. Glazer said their technique avoids some of these pitfalls because it employs oligonucleotides that are short, synthetic DNA molecules that are easier to insert into cells and do not require viruses for their delivery. Importantly, the new technique fixes the defect in the existing gene so it can be expressed in a natural manner, Glazer noted.

Other researchers on the study from Yale contributing to the study were Jean Y. Kuan, Pallavi. S. Lonkar and Diane Krause. Researchers from the National Institute on Aging, University of Kansas, University of Copenhagen in Denmark, and University of North Carolina also were contributing authors. The work was funded by the National Institutes of Health.


Comparison of the mismatch-specific endonuclease method and denaturing high-performance liquid chromatography for the identification of HBB gene mutations

March 13, 2009

Courtesy by: 7thspace.com

Beta-thalassemia is a common autosomal recessive hereditary disease in the Meditertanean, Asia and African areas. Over 600 mutations have been described in the beta-globin (HBB), of which more than 200 are associated with a beta-thalassemia phenotype.

Results: We used two highly-specific mutation screening methods, mismatch-specific endonuclease and denaturing high-performance liquid chromatography, to identify mutations in the HBB gene.

The sensitivity and specificity of these two methods were compared. We successfully distinguished mutations in the HBB gene by the mismatch-specific endonuclease method without need for further assay.

This technique had 100% sensitivity and specificity for the study sample.

Conclusions: Compared to the DHPLC approach, the mismatch-specific endonuclease method allows mutational screening of a large number of samples because of its speed, sensitivity and adaptability to semi-automated systems. These findings demonstrate the feasibility of using the mismatch-specific endonuclease method as a tool for mutation screening.


Red Cross secy offers his blood and toil for thalassemia

March 12, 2009

Courtesy by: TimesofIndia
Ahmedabad: On 26/7, Mahesh Trivedi was a busy man. Till 2 am, he was managing things at Red Cross as people, many first-timers, rushed in to donate blood for the blast victims.

But, his real mission in life is tackling thalassemia and exhorting people to donate blood. Gregarious and blessed with a hearty sense of humour, the honorary secretary of Red Cross Society, Ahmedabad, is a popular man and this helps him spread his message.

“Before getting married, couples should first take a thalassemia test. If both are thalassemia minor, the girl should tie a rakhi to the boy instead of them exchanging rings,” he joked recently while addressing students of MG Science College. His light take on the grave subject had the youngsters in splits, but would also have led them to ponder.

Trivedi, 69, who retired as controller of examination of an Industrial Training Institute (ITI), delivers at least 90 lectures a year in schools and colleges in the state.

“I have been associated with Red Cross since 1969. After retirement, I decided to work full-time ,” says the man who doesn’t believe in wasting a moment.

Red Cross recently launched a project to prevent birth of thalassemia major children by 2020 in collaboration with Ahmedabad district panchayat. The idea is to eradicate thalassemia from the state. Trivedi is playing a major role in the project, the key to which is raising awareness levels.

This year, Ahmedabad Red Cross celebrates the silver jubilee of its blood transfusion services for those afflicted with thalassemia. So far, it has adopted more than 700 thalassemia major children. They are provided blood without replacement, free blood transfusions and oral tablets. And, if any child is in trouble , it’s Trivedi who is contacted.

“This kind of devotion is rare. Others are inspired by him because he sets an example by his own actions . He’s the right man to promote blood donation, as he has himself donated 117 times,” says Mukesh Patel, president of Red Cross Society, Ahmedabad.


Consanguineous marriages and endemic malaria: can inbreeding increase population fitness?

March 12, 2009

Courtesy by: 7thspace.com

The practice of consanguineous marriages is widespread in countries with endemic malaria. In these regions, consanguinity increases the prevalence of alpha+-thalassemia, which is protective against malaria.

However, it also causes an excessive mortality amongst the offspring due to an increase in homozygosis of recessive lethal alleles. The aim of this study was to explore the overall effects of inbreeding on the fitness of a population infested with malaria.

Methods: In a stochastic computer model of population growth, the sizes of inbred and outbred populations were compared. The model has been previously validated producing results for inbred populations that have agreed with analytical predictions.

Survival likelihoods for different alpha+-thalassemia genotypes were obtained from the odds of severe forms of disease from a field study. Survivals were further estimated for different values of mortality from malaria.

Results: Inbreeding increases the frequency of alpha+-thalassemia allele and the loss of life due to homozygosis of recessive lethal alleles; both are proportional to the coefficient of inbreeding and the frequency of alleles in population. Inbreeding-mediated decrease in mortality from malaria (produced via enhanced alpha+-thalassemia frequency) mitigates inbreeding-related increases in fatality (produced via increased homozygosity of recessive lethals).

When the death rate due to malaria is high, the net effect of inbreeding is a reduction in the overall mortality of the population.

Conclusions: Consanguineous marriages may increase the overall fitness of populations with endemic malaria.


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