Thalassemia and sickle cell anemia in Swedish immigrants: Genetic diseases have become global.

AIMS

Some 15% of the Swedish population is born outside Sweden, originating from all continents of the world. Thalassemia and sickle cell anemia constitute the most common inherited recessive disorders globally and they are endemic in areas of Africa and Asia, origins of many immigrants to Sweden. We aimed at investigating the origins of the Swedish sickle cell and thalassemia patients.

METHODS

Patients were identified using data from the Swedish Hospital Discharge Register since 1987 and from the Outpatient Register since 2001 up to year 2010.

RESULTS

A total of 3064 persons were diagnosed with thalassemia. The incidence was highest, 62.9/100,000 for immigrants from Thailand, followed by Iraqis (47.1/100,000); the rate was 0.7/100,000 among those born in Sweden. The total number of sickle cell anemia patients was 584 and the highest rate of 13.0/100,000 was found for Sub-Saharan immigrants. For thalassemia, 363 of the patients were siblings, while for sickle cell anemia, 180 were siblings.

CONCLUSIONS

The data showed that >90% of sickle cell and thalassemia patients were first- or second-generation immigrants to Sweden and the endemic regions for these were the origins of immigrants with the highest incidence. Global immigration provides global challenges to national health care systems.