Bahrain Medical Bulletin, Vol. 33, No. 1, March 2011
Prevalence of Abnormal Hemoglobins among Students in Bahrain: A Ten-Year Study
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Shaikha Salim Al Arrayed, MB, ChB, DHCG, PhD*
Background: Sickle cell disease (SCD) and thalassemia are common in the Arab countries.
Objective: The aim of this study is to evaluate the prevalence of abnormal hemoglobin in secondary school students in Bahrain and to compare the prevalence rates from 1999-2008.
Design: Prospective study.
Setting: Hematology Laboratory at Salmaniya Medical Complex.
Method: The students of the 11th grade (2nd grade in secondary schools), during 1999-2008 were screened. Hb Chromatography was done by HPLC. Informed consents were obtained from the parents.
Result: Sixty thousand and four hundred twenty-four (60,424) students were screened. The most common type of hemoglobin was hemoglobin A, found in 50756 (84%) of the students. The second was Hb S, the average prevalence of SCD was 1.13%, sickle cell trait was seen (SCT) in 13.3%. SCT in 1999 was 13.81 and in 2008 it was 12.8.
Hb D heterozygous was found in 306 (0.51%) of the screened individuals. Hb D homozygous was found in 17 (0.03%). Hb EA heterozygous was found in 84 (0.14%), while Hb E homozygous was found in 3 (0.005%) of the students.
Conclusion: The prevalence of SCD among the age groups (16-18 years) revealed a significant decline during these ten years period P= .000. The continuation of the screening and education efforts might reduce the prevalence further, if not eliminate it. SCD in 2000 was 1.3 and in 2008 it was 0.81.
Bahrain Med Bull 2011; 33(1):
Falciparum malaria was endemic in Bahrain until 1970, but great efforts by the government to eliminate it proved to be eventually successful. The malaria associated genetic defects of red cells, such as SCD, thalassemia and glucose 6-phosphate dehydrogenase deficiency (G6PD), were expected to be common1-4.
* Clinical Geneticist
Salmaniya Medical Complex
Kingdom of Bahrain
The newborn screening study conducted in Bahrain during 1984-1985 revealed 2.1% prevalence rate of SCD. According to the statistics, 200 babies born every year suffered from SCD, with 11.2% being carriers of the abnormal gene for SCD, and 20% have G6PD deficiency. The carrier status for beta thalassemia was 2-4% in a premarital counseling study conducted in 19942-5.
The aim of the study was to determine the prevalence of common genetic blood disorders (thalassemia and sickle cell anemia) among students.
This is a cross sectional interval study, performed annually for a period of ten years. Nearly six thousand students were screened each year for thalassemia and sickle cell anemia. Sixty thousand and four hundred twenty-four (60,424) students were screened.
Informed consent was taken from the parents of children under 18 years of age and those over the age of 18 years were given the choice. The test was applicable for all students of the 11th grade. The results were kept confidential between the researcher's team, the student and his family.
Personal characteristics were documented. Each student received a card with the result which could be maintained throughout life. The schools received reports about the prevalence of these diseases in their school.
The obtained data were coded, processed and analyzed by SPSS.
Sixty thousand and four hundred twenty-four (60,424) students were screened. About 85% of the parents granted permission to test their children. The numbers of students screened yearly during 1999-2008 were 5685, 5694, 6244, 5894, 5418, 6237, 6358, 6352, 6376 and 6166. Male to female ratio was 1:1.2. Hb A was the most common type of hemoglobin.
The average prevalence of SCD was 1.13%, and the average prevalence of SCT was 13.3%, see Table 1.
Table 1: Sickle Cell Prevalence among Students in Bahrain (1999 - 2008) Year
No. of students