|Year : 2015 | Volume
| Issue : 2 | Page : 100-107
Genetic counselling in anaemia & thalassemia
Medical & Genetic Counsellor, Dept. of Oncology, Vydehi Institute of Medical Sciences & Research Centre, Bangalore, Karnataka, India
|Date of Web Publication||5-Jul-2017|
Medical & Genetic Counsellor, Dept. of Oncology, Vydehi Institute of Medical Sciences & Research Centre, Bangalore, Karnataka
Source of Support: None, Conflict of Interest: None
Objective: 1. To identify the common type of anaemia in our population and promote appropriate counselling for an effective plan of management & treatment. 2.To establish how thalassemia is diagnosed and assess type of counselling received among the thalassemic families and to provide appropriate Genetic Counselling. Method: Information was obtained from Anemic and Thalassemic patients to assess their awareness regarding their pathophysiology and assess what type of counselling they received, from different centres in Hyderabad, India. Result: It was found that after counselling, the patients and their attenders were more receptive to undergoing treatment for anaemia and genetic testing for thalassemia. Conclusion: Extended family screening, prenatal diagnosis and carrier testing should be explained and advised and the centres offering these tests should also be informed.
Keywords: Anaemia, Thallasemia, Genetic counselling
|How to cite this article:|
Hatti J. Genetic counselling in anaemia & thalassemia. Acta Med Int 2015;2:100-7
| Introduction|| |
Anaemia is a decrease in number of red blood cells (RBCs) or less than the normal quantity of haemoglobin in the blood. However, it can include decreased oxygenbinding ability of each haemoglobin molecule due to deformity or lack in numerical development as in some other types of haemoglobin deficiency. Anaemia is a global public health problem seen both in developing and developed countries with major consequences for human health as well as social and economic development. It occurs at all stages of the life cycle, but is more prevalent in women and young children. In 2002, iron deficiency anaemia (IDA) was considered to be among the most important contributing factors to the global burden of disease. Anaemia is the result of a wide variety of causes and globally, the most significant contributor is iron deficiency. It is generally assumed that 50% of the cases of anaemia are due to iron deficiency, but the proportion may vary among population groups and in different areas according to the local conditions. The main risk factors for IDA include a low intake of iron, poor absorption of iron from diets high in phytate or phenolic compounds, and period of life when iron requirements are especially high (i.e. growth and pregnancy).
Among the other causes of anaemia, heavy blood loss as a result of menstruation, or parasite infections such as hookworms, ascaris, and schistosomiasis can lower blood haemoglobin (Hb) concentrations. Acute and chronic infections, including malaria, cancer, tuberculosis, and HIV. can also lower blood Hb concentrations. The presence of other micronutrient deficiencies, including vitamins A and B12, folate, riboflavin, and copper can increase the risk of anaemia.
Hemoglobinopathies are the most commonly inherited genetic disorders in which the production of normal haemoglobin is partly or completely suppressed because of defective synthesis of one or more of its component globin chains. The most common ones are Thalassemia and Sickle-cell disease. Hemoglobinopathies imply structural abnormalities in the globin proteins. Thalassemia is a quantitative problem of globin synthesized and usually result in under production of normal globin proteins, often through mutations in regulatory genes. It is also known as Cooley's anemia, after Cooley and Lee who first described the condition in 1925.
Thalassemia is an inherited autosomal recessive blood disease that originated in the Mediterranean region. In thalassemia the genetic defect, which could be either mutation or deletion, results in reduced rate of synthesis or no synthesis of one of the globin chains that make up hemoglobin. This can cause the formation of abnormal haemoglobin molecules, thus causing anemia, the characteristic presenting symptom of the thalassemias [Figure 1].
The commonest thalassemic mutations in Indian ethnic groups is IVSI-5, IVS 1-5, Cd 5, Cd 15, Cd 30, Cap 11, Del 619, Fr 8-9, Fr 16 and Fr 4142.
4.5% of population worldwide is Thalassemia minors (World Health Organization). There are over 35 million carriers of this abnormal gene for Thalassemia in India, i.e., 1 in 25. Around 10-15,000 babies with hemoglobinopathies are born in India every year. Generally, Thalassemias are prevalent in populations that evolved in humid climates where malaria was endemic, but affects all races.
Beta Thalassemia is more prevalent in India. Around 10,000 to 12,000 thalassemic children are born every year in India. It is very high among certain ethnic groups like Punjabis, Sindhis, Gujaratis, Bengalis, Parsis, Lohanas and in certain tribes.
| Methodology|| |
The present study was taken up at Thalassemia and Sickle Cell Society, Hyderabad, an NGO for assessing how thalassemic patients were identified and diagnosis confirmed.
Data from Haematology department of Kamineni Hospitals, L B Nagar, Hyderabad, and also at Indian Institute of Health and Family Welfare which had carried out a project on Anemia were obtained.
Information was obtained from Anemic and Thalassemic patients to assess their awareness regarding their pathophysiology and assess what type of counselling they received.
| Observations & Results|| |
Data was collected from the Haematology Department of Kamineni Hospital (Feb-April 2011) from the Complete Blood picture samples which were sent for evaluation. A total of 6252 samples were recorded. 2240 samples belonged to females in the age range of new borns to 90 years. The analysis has been carried only for female patients [Chart 1].
The haemoglobin values observed were between 5-14 g/dL, 13g/dL was seen in only 2 cases and only 1 case had 14g/dl.
Individuals having hemoglobin above 12g/dl were considered normal, mild anemia was taken as values between 10-11g/dl, 8-9 g/dL were categorised as moderately anemic and below 7g/dl were considered as severely anemic [Chart 2].
Only 50% of the women appear to have hemoglobin in the normal range. Moderate to mild anemia is mostly seen in women of reproductive age (21-50years). This may be because of blood loss during menstruation, pregnancy and peri menopausal menorrhagia [Chart 3].
The consequences of anemia for women include increased risk of low birth weight or prematurity, perinatal and neonatal mortality, inadequate iron stores for the newborn, increased risk of maternal morbidity and mortality, and lowered physical activity, mental concentration, and productivity.
Data regarding anemia was collected from study carried out at a diagnostic centre on 1000 women in the age group of 18 to 25 years [Chart 4]. 38% were found to have anemia (taken as <12g/dl), 40 had abnormal HPLC's and 3 were identified as thalassemic carriers [Chart 5].
An earlier study conducted by a NGO-International Union for Health Promotion and Education (IUHPE) on a total of 5128 adolescent girls aged 10-18 years showed in the graph below.
Severe anemia (<8g/dl Hb) was seen in 389 girls. This shows that poor dietary habits may be a contributing factor for a decreased haemoglobin level. This may be because most of these girls, being from a low socio-economic background do not have their daily meals properly. Therefore, supplementation of iron tablets can prove to be effective in the rise in hemoglobin levels.
Information collected from 17 patients of anemia:
The most common type of anemia observed was the iron deficiency anemia.
From the information obtained after discussion it appeared that maternal health care centres provided them with iron supplements but did not give them information regarding anemia, appropriate diet, symptoms and consequences. Health care providers seem to play a very limited educational role while, media seems to be the main source of information for most of the people. The role of lectures and public information leaflets also seem to have a limited impact as the source of knowledge as most of the women in the study were illiterate.
Knowledge regarding iron supplements and its effect on mother and foetal health was also at low level. The women were also unaware of suitable local diet which would help elevated anaemia. Adverse effect of tea, coffee, and milk on iron absorption was also not indicated nor were they aware that vitamin C rich fruit juice like that of lime and other citrus fruits improves absorption and reduces GI tract symptoms associated with iron supplements.
The Thalassemia and Sickle Cell Society, Hyderabad, has a total of 1285 registered families belonging to different districts of Andhra Pradesh.
Maximum patients were from Hyderabad which is understandable as the centre is situated in this city, followed by Adilabad indicating that the local group, which includes the parents of the affected children, is very active. Patients from Khammam, Nalgonda and Karimnagar are also relatively high [Chart 6].
Out of the registered cases, information from 71 patient families is given below.
Among the 71 families interviewed- 29 were non consanguineous marriages and their children are thalassemia major because of different ethnic groups and social community. Therefore, extended family screening for the non consanguineous marriages must be recommended [Chart 7] and [Chart 8].
Mode of Identification of Thalassemia Patients:
- Following were the most commonly seen symptoms-
- The child had-Pyrexia, vomitings, lethargy and loss of appetite.
- Taken to a local clinician.
- Routine CBP done in view of above mentioned symptoms.
- Abnormal levels of hemoglobin seen in the CBP,
- A hemogram is adviced followed by Hb electrophoresis
- After confirmation of thalassemia the families are referred to Thalassemia Society.
None of the families received any counselling regarding thalassemia at the primary clinician level.
Information Obtained from Families with Thalassemia when Interviewed Indicated the following
- Most of them are aware that thalassemia is familial but they are unclear about the mode of inheritance and hence blamed the other partner for the disease.
- Carrier testing of parents after confirming disease in the proband was done because the clinician had asked them to do so and in some cases to indicate to the partner that both are carriers.
- Inadequate knowledge about carrier testing failed to help in extended family testing as the parents could not explain to their relatives the importance of this.
- There is no genetic counsellor attached to the Thalassemia Society, hence proper counselling regarding recurrence risk, molecular testing and prenatal diagnosis was not provided.
- Financial constraints were a cause for not doing some of the tests even when they were aware of the tests.
| Discussion|| |
Hb concentration is the most reliable indicator of anaemia. Measuring Hb concentration is relatively easy and inexpensive, and this measurement is frequently used as a proxy indicator of iron deficiency. However, anaemia can be caused by factors other than iron deficiency. In addition, in populations where the prevalence of inherited haemoglobinopathies is high, the mean level of Hb concentration may be lowered. In addition to the measurement of Hb concentration, the causes of anaemia need to be identified considering that they may vary according to the population. More than 50% of the patients were females.
Being a multifactorial disease, correcting anaemia often requires an integrated approach. In order to effectively combat it, the contributing factors must be identified and addressed. In settings where iron deficiency is the most frequent cause, additional iron intake should be usually provided through iron supplements to vulnerable groups; in particular pregnant women and adolescent girls.
Food based approaches to increase iron intake through food fortification and dietary diversification is an important and sustainable strategy in order to prevent IDA in pregnant women. In settings where iron deficiency is not the only cause of anaemia the iron levels should still be monitored.
Strategies should include addressing other causes of anaemia and should be built into the primary health care system and existing programmes. These strategies should be tailored to local conditions, taking into account the specific etiology and prevalence of anaemia in a given setting and population group.
Iron Deficiency (ID) during pregnancy is likely to lead to continuation of the deficiency during lactation and longterm, as it takes time to replete iron stores once they have been exhausted. For this reason alone, it is important to prevent the development of ID during pregnancy.
It is apparent that iron deficiency will be seen often, enough to require a clear set of guidelines for recognition and management as the adopted strategies seems to lack good management. The findings also suggest a degree of uncertainty amongst those health professionals who deal with pregnant women as to iron deficiency anemia's clinical consequences and the best policy regarding identification and prevention.
A screening program should be implemented for measuring the Hb and serum ferritin levels in all the adolescent girls and for pregnant women in their second and third trimesters.
It is essential that physician or other health professionals must pay more attention to teach pregnant woman good long term dietary habits as a part of an overall approach to health promotion. However, once ID is established, a period of iron supplementation is almost certainly necessary in order to improve the iron status of the mother and prevent further consequences of ID.
It is also of great importance to encourage women for early registration during pregnancy and also to attend postnatal visits during lactation for close supervision and effective follow-up. Counselling should be provided to girls when they reach adolescence so that they are aware of the risk factors like late puberty, the causes for anemia, proper dietary plans to prevent anemia. Such counselling sessions should be provided in schools and colleges where even the parents are made aware of the proper management and treatment of anemia so that further complications can be prevented [Figure 2].
|Figure 2: Students consume the IFA tablet in the presence of the teacher|
Click here to view
Thalassemia requires a heightened awareness and sensitivity about its effects. All young people of marriageable age should get a screening test done to find out whether they have the trait or not. Having Thalassemia trait is innocuous as long as two people with Thalassemia trait do not get married (because of 25% probability of giving birth to Thalassemia major child)., In a couple, both with Thalassemia minor, the birth of Thalassemia major child can still be prevented by ante-natal check-up and termination of pregnancy if the fetus is Thalassemia major by doing the prenatal diagnosis such as chorionic villus sampling (first trimester <12 weeks), amniocentesis (second trimester 16-18 weeks) or fetal cord blood sampling (third trimester). From samples obtained through these 3 methods, DNA is extracted and molecular analysis is done to identify the affected fetus.,,
Thalassemia can be prevented by implementing programs like education in schools and colleges, screening protocols, adolescent screening, pre-marital counselling, and prenatal/ antenatal counselling. Consanguineous marriages are practised more in India. 53% of thalassemic cases recorded at the Thalassemia Society are a result of consanguineous marriage, however 47% of the incidence is attributed to ethinicity, since people get married within their communities itself.
India being a developing country, majority of the population falls under low socioeconomic class with a monthly income of Rs.2000-Rs.4000. As a result of which, families are not able to provide proper treatment for their children, as a result mortality rate for thalassemia is still persistent (treatment for a child per year on an average costs Rs.1.25 laks).
Creating awareness by varied means of premarital counseling, including in school, colleges, and most important is the need for a trained genetic counsellor to enable all this. Genetic counsellors should be available at all the blood transfusion centres, various thalassemia societies, pediatric and gynecology set ups which are dealing with high pregnancy risks.
Procedure of Counselling in Thalassemia
- Patient's detailed medical history should be taken which includes age of diagnosis, symptoms, tests done, number of blood transfusion taken, chelating drugs advised.
- A pedigree of the patient along with the family history should be taken.
- Extended family screening, prenatal diagnosis and carrier testing should be explained and advised and the centres offering these tests should also be informed.
- Their dietary habits should also be noted.
- Counselling should include information regarding the inheritance pattern, recurrence risk (25% chance of having an affected child, 50% chance of having an asymptomatic thalassemic carrier child and 25% chance of having a completely normal child and that these percentages applies for every pregnancy), treatment and management.
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[Figure 1], [Figure 2]