Launch of Mission Sickle Cell Anaemia & Beta-Thalassaemia Free INDIA.
Thalassaemia
Thalassemia is an inherited disorder of autosomal recessive gene disorder caused by impaired synthesis of one or more globin chains. The impairment alters the production of haemoglobin (#Hb). Thalassemia causes varying degrees of anaemia, which can range from significant to life-threatening.
People of Mediterranean, Middle Eastern, African, and Southeast Asian descent are at higher risk of carrying the genes for thalassemia. Southeast Asia accounts for about 50% of the world’s carriers while Europe and the Americas jointly account for 10-13% of the world carriers. It is estimated that there are almost 3.6 to 3.9 crore carriers of β-thalassemia in India, and about 10000 to 15,000 babies with β-thalassemia major are born each year and around 150000 are patients with Thalassemia major. For sickle cell disease, there are about 25,00,000 carriers of the gene (Hemoglobin AS), and about 1,25,000 patients of sickle cell disease.
β-thalassaemia is the most common gene disorder in the Indian population. Higher frequency has been observed in certain communities, such as Sindhis, Punjabis, Muslims, Gujaratis, Bengalis, Mahars, Kolis, Saraswats, Lohanas and Gaurs.
Types of Thalassemia
There are two major types of thalassemia namely: 1) alpha and 2) beta.
They are named after defects in these protein chains of haemoglobin (Hb). Four genes are needed to make enough alpha globin protein chains.
1) Alpha thalassemia:
People whose haemoglobin does not produce enough alpha protein have alpha thalassemia. This occurs when one or two of the four genes are missing. If more than two genes are missing, the result is moderate to severe anaemia. The most severe form of alpha thalassemia is known as “alpha thalassemia major or hydropsfetalis”. Babies with this disorder usually die before or shortly after birth.
2) Beta thalassemia:
People whose haemoglobin does not produce enough beta protein have beta-thalassemia. If one of your beta haemoglobin genes is defective, one has mild signs and symptoms. This condition is called beta-thalassemia minor or beta-thalassemia trait. If both of your beta haemoglobin genes are defective, your signs and symptoms will be moderate to severe. This condition is called “beta-thalassemia major or Cooley's anaemia”. Babies born with two defective beta haemoglobin genes usually are healthy at birth, but develop signs and symptoms within the first two years of life.
Nearly 36 mutations are reported in the beta Thalassemia Indian population of which eight account for 95% of the cases. Alpha Thalassemia is generally caused by deletions of the alpha globin gene.
Signs & Symptoms of Thalassaemia
Signs and symptoms of thalassemia depend on the type and can vary from none to severe.
Some of the most common symptoms include:
1. Bone deformities especially face
2. Fatigue
3. Heart problems
4. Increased risk of infection
5. Iron overload
6. Pale appearance or yellow skin
7. Slow growth rates
8. Weakness
Who should get screened?
Screening is done in the following groups:
1. High-risk individuals, families and communities
2. Parents and relatives of thalassaemia.
3. Carriers of thalassaemia who have or do not have family history
4. Voluntary social workers
5. Married or unmarried individuals / premarital screening
6. Couples at risk
Treatment
The treatment for thalassemia depends on the type and severity of the disorder involved. For instance, treatment for those with a more severe form of the disease includes:-
1. Blood transfusions (#BT) & Iron chelation therapy (#ICT):
Regular blood transfusions are the only treatment available to patients with thalassemia. It allows thalassemia patients to live relatively normal lives but they require transfusions every 2-4 weeks depending on the individual’s consumption of the infused cells. However, in thalassemia, once these red blood cells are broken down BT leave patients with an excess of iron in their bodies. This dangerous side effect is known as “iron-overload” which affects the heart and liver.
Nowadays, drugs designed to remove excess iron (iron chelators) have significantly changed the prognosis of thalassemia major. Patients can grow and develop normally, with relatively normal heart and liver functions. Two medicines are used for iron chelation therapy. Deferoxamine is a liquid medicine that's given slowly under the skin, usually with a small portable pump used overnight. This therapy takes time and can be mildly painful. Side effects include loss of vision and hearing.
Deferasirox is a pill, dissolved in water or juice and taken once daily, preferably on an empty stomach. Side effects include headache, nausea, vomiting, diarrhoea, joint pain, and fatigue. One may need to take folic acid supplements in addition to blood transfusions and/or iron chelation therapy.
2. Bone marrow transplant (#BMT):
Blood and marrow transplant replaces abnormal or faulty cells with healthy ones from another person (a donor) but only a few people can find a good match among donors and have the risky procedure. Bone marrow transplants can cost anything between Rs.20 lakh and Rs.35 lakh.
3. Surgery:
The spleen becomes too active and starts to destroy the RBCs, transfusions become less effective. Then it becomes necessary to take the spleen out called "Splenectomy".
4. Gene Therapy:
A group of researchers around the globe are working to develop gene therapy against thalassaemia patients and several trials are ongoing which are to some extent giving promising results.
Diagnosis
Following biochemical, immunological and molecular tests should be performed to assess thalassemia in parents and in foetus:-
1) Complete blood count
2) Hb variant analysis
3) DNA analysis using blood of both parents:-
DNA analysis using chorionic villi sampling (CVS) and amniotic fluid (AF) in prenatal procedures because prevention of this disease in the next generation is important.
2) Prenatal Testing :
Here’s how you will know if your baby will have thalassemia or not:
1. If you or your spouse is thalassemia minor: There are equal chances of your baby either inheriting your defective genes or your baby may not inheriting the defective genes at all. However, your baby will not be a thalassemia major in this case.
2. If you and your spouse both are thalassemia minor: The chances are one in four, that your baby does not inherit the defective genes at all. Though your baby has the same amount of chances to be born with thalassemia major. However, the chances are one in two that your baby is born with thalassemia minor.
The above-mentioned possibilities remain the same in each case of pregnancy, of the same couple. This means no matter how many kids the same couple has, the above-mentioned possibilities will apply in each case.
Prenatal diagnosis determines the health and condition of an unborn fetus. Specifically, prenatal diagnosis is helpful for:-
• Determining the outcome of the pregnancy
• Planning for problems that may occur in the newborn infant
• Deciding whether to continue the pregnancy or not
• Finding conditions that may affect future pregnancies
1. Chorionic Villus Sampling (#CVS) :
In the CVS procedure, under ultrasound guidance, a catheter is passed via the vagina through the cervix and into the uterus to the developing placenta. Alternative approaches are transvaginal and transabdominal. The introduction of the catheter allows sampling of cells from the placental chorionic villi. The CVS can be safely performed between 9.5 and 12.5 weeks gestation.
CVS has the disadvantage of being an invasive procedure, and it has a small but significant rate of morbidity for the fetus with a loss rate of about 0.5 to 1% higher than for women undergoing amniocentesis. CVS can be also associated with limb defects in the fetus. There is also the possibility that maternal blood cells in the developing placenta will be sampled instead of fetal cells and confound chromosome analysis.
2. Amniocentesis :
This is an invasive procedure in which a needle is passed through the mother's lower abdomen into the amniotic cavity inside the uterus. For prenatal diagnosis, most amniocenteses are performed between 14 and 20 weeks gestation. However, an ultrasound examination always proceeds amniocentesis to determine gestational age, the position of the fetus and placenta, and determine if enough amniotic fluid is present. The increased risk for fetal mortality following amniocentesis is about 0.5%.
Why is Prevention of Thalassaemia better than Treatment?
Ideally, every thalassemia major patient spends Rs. 2 Lakh annually for transfusion, chelation and blood tests. Every year 52 pints of blood are required per patient and the annual cost for this on average is Rs.28000-30000. In addition to this cost, the patient has to face mental and social taboos. Indian govt. every year a huge amount is to treating new and existing patients and that money has to be paid by regular taxpayers. By looking at the recent trend of this disease very soon this amount will be much higher.
So by considering prevention is better than cure, we need to start doing prenatal diagnostic testing (through CVS / amniotic fluid) by molecular method. From this, we can eliminate the number of thalassemia patients from our INDIA in the next few years.
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