oa Distribution of Hemoglobinopathies and Thalassemias in Qatari Nationals Seen at Hamad Hospital in Qatar

Several reports indicate that haemoglobinopathies and thalassemias are the most common genetic abnormalities in the population of the Arabian- Peninsula. However the exact frequencies of these abnormalities among the Qatari population has not yet been determined. We surveyed the results of all hemoglobin-electrophoresis performed in Hematology laboratory at Hamad Hospital over a period of 78 months (Jan.1994- June.2000) together with the results of all other relevant tests to highlight the distribution of these disorders among the Qatari patients seen at Hamad Hospital.

The size of the group analyzed was 3275 of whom 1702 were Qatari and 1573 were non-Qatari residents of different nationalities. The survey of Qatari results revealed that 30.43% of all Qatari patients tested carry fi-thalassemia (minor, intermedia or major), 12.28% carry oc-thalassemia (minor or intermedia) while 0.53% were labeled as having Hereditary Persistence of Fetal Hemoglobin (HPFH). fithalassemia is the most common type of thalassemic disorders seen in the Qatari patients, accounting for 71.25% of all thalassemias encountered in this group.

Out of Qatari patients tested 16.33% were found to carry a structurally abnormal hemoglobin variant of one type or another. Sickle cell hemoglobin (Hb-s) is the most common structural hemoglobin variant detected where it is found in 14.63% of those tested and constituting about 83.97% of all structural hemoglobin variants detected. Hb.D was found in 1.41% of those tested and constituted 12.42% of all structural hemoglobin variants detected in this group. Other structurally abnormal hemoglobin variants such as Hb. E and Hb. C were less common. As expected, almost all possible combinations between different types of structural hemoglobin variants and different types of thalassemias could be identified.

Considering the fact that the hematology laboratory at Hamad Hospital is the only laboratory in the State of Qatarthat performs hemoglobin- electrophoresis we hope that this study will reflect for the first time a reasonable idea about the prevalence of thalassemia and other types of hemoglobinopathies among the indigenous Qatari population and help to provide a comprehensive baseline information for any proper future epidemiological studies to establish the exact frequencies of these genetic disorders among Qatari nationals and for any future molecularbased studies for elucidation of the molecular basis of these disorders in this population.