Clinical and laboratory features of sickle cell disease in the Netherlands

ABSTRACT

Out of about 200 patients with sickle cell disease (SCD) in the Netherlands, 6 percent are non-negroid patients from Turkey. 83 were assessed clinico-haematologically regarding the type of SCD, ethnic origin, concurrent O-thalassaemia (O-thal), and type of sickle cell gene (á-chromosome). 54 patients had homozygous sickle cell (SS),1 sickle cell haemoglobin D (SD) Punjab, 5 sickle cell á§-thalassaemia (Sá§-thal), 5 sickle cell á+-thalassaemia (Sá+-thal) and 18 sickle cell haemoglobin C (SC) disease. 14 percent of the 83 patients were from Turkey, the others were of West Indian and African origin, most (73 percent) of whom were from Surinam. The Netherlands may be the only country in the world where non-negroid SCD patients are present in such a proportion to negroid SCD patients. O-thal was detected in 16 patients and in 14 of their relative with sickle cell trait. Four main types of ás-chromosomes were identified Benin, Central African Republic, Senegal and Saudi Arabia types. SS and Sá§-thal disease ran a more severe course than Sá+ +-thal and SC disease. No clinical difference was ascribable to ethnic origin, O-thal or HbF-level but in each ethnic group there were some patients with a remarkably mild course of SS disease, which was related to the type of ás-chromosome. These were the Senegal and Saudi Arabia ás-chromosomes. Proper differentiation between genotypes is of prognostic and therapeutic relevance,especially in SC disease as it is sometimes discovered too late. A proper screening program is encouraged not only for all negroid inhabitants or immigrants, but also for non-negroid immigrants especially from Turkey.(AU)