Author: Arica, Seçil Gunher
Date published: February 1, 2012
Hemoglobinopathies are amongst the most prevalent of all human genetic disorders resulting from structural changes or abnormal synthesis of polypeptide chain of the hemoglobin molecule (1). Although it is highly prevalent in tropical and subtropical regions, became a common problem all around the world because of the migrations (2- 4). Hemoglobinopathy is amongst the most common hereditary hematologic disorder in country and especially in Cukurova region an important health problem. In Turkey, there are approximately 1.300.000 carriers and 4000 patients (5, 6). According to the results of the survey carried out by Ministry of Health and National Hemoglobinopathy Council, mean beta-thalassemia trait prevalence of the sixteen mostly common centers in Mediterranean region was 4.3% (4-7). Prevention of hemoglobinopaties that are important causes of mortality and morbidity with premarital screening and prenatal diagnose is possible. Thus determinations of carriage and premarital screening tests in highly prevalent regions have great importance (8). For this reason a first step Hemoglobinopaty Control Program was established in 33 provinces including Hatay regarding the disease prevalence rates in 2002 (4).
The aim of this study is to determine the prevalence of hemoglobinopathy trait evaluating premarital screening results of Hatay region.
Material and Methods
The study sample comprised the couples attending to the Mother and Child Health Care Center in Hatay for premarital hemoglobinopathy screening from 2004 to 2009. Hemoglobin chain analyses of 87.830 couples were evaluated. The blood samples were collected at the main Center in Antakya. The blood samples at the districts are sent to the center with a carrier by obeying the cold transport and their evaluated results at the center again transported to the districts by a carrier. The required information about the subject is given during the application and the results are delivered in accordance with the privacy rules. All of the applicants were subjected to the complete blood count and hemoglobin electrophoresis. Hematological parameters were analyzed by Coulter counter and hemoglobin electrophoresis has been performed by MALTA Celloclear Alkaline Electrophoresis. Hemoglobin A2 was analyzed by micro column technique from Bio Systems kits and hemoglobin F was assayed by alkaline denaturation technical. The blood samples with mean corpuscular volume (MCV) levels below 80 fL were analyzed for hemoglobin A2 (HbA2) and hemoglobin F (HbF). People who had elevated HbA2. 3.5 and/or HbF.2.0 were diagnosed as À thalassemia trait. Sickle Cell Hemoglobin (HbAS) indicates as sickle cell trait and Sickle cell disease (HbSS) indicates as sickle cell anemia with hemoglobin electrophoresis. Because of the high costs, gene analyses were done only cases those with normal HbA2 levels but MCV <80 fl or HbF >2%
Ethical consent was obtained (Mustafa Kemal University Medical Faculty Ethics Committee (02.10.2010/153).
175.660 people (87.830 male, 87.830 female) were screened as a part of premarital screening program in Hatay region in six years. Beta-thalassemia trait was found in 13.921 people (7.9%). Total sickle cell anemia trait was found in 6.074 people (3.4%). 3208 (3.6%) of them were male, while 2.866 were female (3.3%) (Table I). The prevalence of sickle cell anemia, beta-thalassemia major, beta thalassemia, alpha thalassemia, alpha thalassemia trait was found 0.35% (n=631), 0.07% (n=132), 0.06 % (n=118), 0.005% (n=9), 0.08% (n=150), respectively.
Beta-thalassemia trait prevalence in districts of Hatay was found as; Antakya 4.409 (2,5%), Reyhanli 1.450 (0,8%), Altinözü 912 (0,5%), Ğskenderun 1.160 (0,7%), Belen 7 (0.003%), Erzin 97 (0.05%), Samandag 1.369 (0,7%), Yayladag 46 (0.03%), Kirikhan 1.360 (0,7%), Dörtyol 976 (0,6%), Hassa 681 (0,4%), others 1.453 (0,8%).
Sickle cell anemia trait in districts was found (Table II, Figure I). The age intervals of the subjects were calculated as follows: age: 17- 20, 14.322 (8.2%), age 21-29, 126.117 (71.8%), age 30-40, 20.074 (11.4%), age over 40, 15.147 (8.6%). Premarital hemoglobinopathy screening was carried out in 27.612 people in 2004, in 28.261 in 2005, in 28.839 in 2006, in 30.733in 2007, in 32.016 in 2008, in 28.199 in 2009. Formal marriage numbers according to years in Hatay region was as follows: in 2004 27.411, in 2005 26.852, in 2006 28.296, in 2007 30.094, in 2008 28.730, in 2009 27.696. In the study period 182, 291, 417, 502, 598, 644 couples were found to be carriers, respectively (Table III). 72 newborns with beta-thalassemia were diagnosed as a result of the marriage of the carrier couples in 6 years.
Thalassemia was first described in a child with deep anemia, splenomegamia and characteristic bone changes in 1925 by Thomas Cooley and Peael Lee (9). The name was originated from the Greek word "thalas" which means Mediterranean because formerly it was thought to be prevalent in the Mediterranean region. Hemoglobinopathies can be classified into thalassemias and abnormal hemoglobinopathies. The latter is consisting of aminoasid change on the globin chain of hemoglobin molecule. The most prevalent abnormal hemoglobins are Hb S, Hb D, Hb E, and Hb C (1). Thalassemia is a genetic disorder characterized with a decrease or a complete loss of synthesis of the globin chains of hemoglobin (10). The most prevalent types are α ve β-thalassemia. β- thalassemia is common in Turkey (11). Abnormal hemoglobins are generally specific to regions and ethnicity. In Turkey, HbS is the most prevalent abnormal hemoglobin type which causes to sickle cell anemia (11). Thalassemia syndromes are the most common monogenetic disorders in human which were described in detail. In the light of the knowledge, not only managing the broad clinical spectrum but also precise decisions using prenatal diagnosis would be possible (12).
The effective methods to prevent autosomal recessive hereditary diseases such as hemoglobinopathies are community education about the disease, determining the carriers by screening, genetic counseling, and prenatal diagnosis (4, 13).
Hemoglobinopathies were controlled; number of new cases was decreased, even eradicated in some countries including Cyprus, Greece and Italy (4, 8). Previous studies showed the efficacy, efficiency and, importance of premarital screening in high risk populations (14).
Beta-thalassemia trait prevalence of Turkey and other Middle Eastern countries were compared and showed in figure II. We can see the high prevalence in Turkey (15). The prevalence of beta-thalassemia trait and sickle cell trait is shown in figure III. They're prevalent in Mediterranean region. Betathalassemia prevalence was found 7.7 % while it was 4.3% in Turkey. Sickle cell anemia trait prevalence was found 10.0% in Adana and 13.6% in Mersin-the cities in Mediterranean region-(4-7). In the present study sickle cell anemia trait prevalence was found 3.4% which is lower than Mediterranean region but higher than Turkey average.
Thalassemia and hemoglobin disorders are one of the common hereditary disorders in our country and all over the world. Although these hereditary disorders are more common in Mediterranean region, studies showed the presence at various rates all around the world. Today the only way for prevention is prenatal diagnosis, therefore hemoglobinopathy control programs were established not only in our country but also all over the world. The main approach of these control programs were identification of the individuals especially in the premarital age.
Antenatal screening programs is common in the Mediterranean populations. The successes of these programs depend on public health education and effective screening programs. Application of these programs in crowded Asian populations like India and southeast countries might be difficult because of faith, culture, and economical factors. Initially education programs should be established and voluntary screening programs should be supported. Following these programs would compose the basic approach on establishment of the development of the national population control programs (9). Public education and acknowledgement studies should be given priority in countries which are composed of different religious, ethnic and cultural diversity like ours.
As a conclusion Hatay is a high risk region for beta-thalassemia and sickle cell anemia. A premarital screening program is of great value to prevent high risk marriages to decrease prevalence of hemoglobinopathies in high risk regions. Also counseling about the antenatal screening and hereditary diseases should be given to disease carrying couples and to the whole population.
Conflict of Interest: None to declare
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Correspondence concerning this article should be addressed to Asisstant Professor Dr. Vefik ARICA; Medical Faculty of the Mustafa Kemal University, 31100, Serinyol, Antakya, Hatay, Turkey | Email: email@example.com | Phone: +90 326 2291000 Fax: +90 326 2455654
Paper publication: 18 February 2012
Seçil Gunher Arica (1), Ebru Turhan (2), Cahit Özer (1), Vefik Arica (3) *, Dilek Benk Silfeler
(4), Ğbrahim Silfeler (5), Ayse Betül Altun (6)
1) Mustafa Kemal University Medical Faculty, Department of Family Medicine, Hatay, Turkey
2) Mustafa Kemal University Medical Faculty, Department of Public Health, Hatay, Turkey
3) Mustafa Kemal University Medical Faculty, Department of Pediatric, Hatay, Turkey
4) Mustafa Kemal University Medical Faculty, Department of Obstetrics and Gynecology, Hatay, Turkey
5) Hatay Hassa State Hospital, Department of Pediatric, Hatay, Turkey
6) Hatay Health Directorate, Child Health and Family Planning Directorate, Hatay, Turkey
* Corresponding Author