From the Guidelines
Hemoglobinopathies are prevalent genetic disorders in Saudi Arabia, with sickle cell disease (SCD) and thalassemias being the most common, and their prevalence varies across different regions. The overall prevalence of hemoglobinopathies in Saudi Arabia can be broken down into:
- Sickle cell disease (SCD): approximately 4.2% carrier rate nationwide, with the highest prevalence in the Eastern province (approximately 17% carrier rate) and varying rates across other regions: 10% in the Southern province, 6% in the Western province, and lower rates in the Central and Northern regions 1.
- Beta-thalassemia: carrier rate ranges from 1-5% nationwide, with certain areas showing higher frequencies.
- Alpha-thalassemia: carrier rates of approximately 30-40% in the Eastern province.
- Other hemoglobinopathies:
- Hemoglobin E: less than 1%
- Hemoglobin D: approximately 1%
- Hemoglobin C: rare, less than 0.5%. These disorders are particularly common due to the high rate of consanguineous marriages in Saudi Arabia, estimated at 55-60%, which increases the likelihood of autosomal recessive inheritance. The geographical distribution reflects historical migration patterns and founder effects, with higher prevalence in coastal and southern regions compared to central areas. The Saudi government has implemented premarital screening programs to reduce the incidence of these disorders, which has helped identify carriers and reduce new cases. It is essential to consider the most recent guidelines, such as the American Society of Hematology 2021 guidelines for sickle cell disease, which discuss the importance of hematopoietic stem cell transplantation (HSCT) as a curative intervention for SCD 1.
From the Research
Prevalence of Hemoglobinopathies in Saudi Arabia
The prevalence of hemoglobinopathies in Saudi Arabia varies by region, with some areas having a higher incidence of certain types of hemoglobinopathies.
- Sickle cell disease is more prevalent in the Eastern region, with a prevalence of 134.1 per 1000 persons examined 2.
- β-thalassemia is also more prevalent in the Eastern region, with a prevalence of 59.0 per 1000 persons examined 2.
- In the Southern region, sickle cell disease accounts for more than 7% of total tests, with a high rate of hemoglobin abnormalities 3.
- A study in Al Majma'ah found that the prevalence of β-thalassemia trait was 0.69% and that of sickle cell trait was 0.32% 4.
Percentage of Each Hemoglobinopathy
The percentage of each hemoglobinopathy in Saudi Arabia is as follows:
- Sickle cell disease: 2.7% of cases and 42.4% of carriers per 1000 persons examined 2.
- β-thalassemia: 0.5% of cases and 18.0% of carriers per 1000 persons examined 2.
- Sickle cell trait: 8.8% of patients with abnormal hemoglobin variants 5.
- β-thalassemia trait: 10.0% of patients with abnormal hemoglobin variants 5.
- α-thalassemia: frequencies ranging from 1 to 58% in Gulf countries, with the highest frequencies reported from these areas 6.
Regional Variations
There are significant regional variations in the prevalence of hemoglobinopathies in Saudi Arabia, with some regions having a higher incidence of certain types of hemoglobinopathies.
- The Eastern region has the highest prevalence of sickle cell disease and β-thalassemia 2.
- The Southern region has a high prevalence of sickle cell disease, with more than 7% of total tests 3.
- The Western and Central regions have a lower prevalence of hemoglobinopathies compared to the Eastern and Southern regions 2.