Neonatal haemoglobinopathy screening in Spain.

The prevalence of variant haemoglobins in Spain is increasing as a result of recent African immigration. Of the 19 regions of Spain, 13 have more than 1% of residents of African origin or ethnicity. Haemoglobinopathy prevalence is heterogeneous. Some cases of sickle cell disease (SCD) and sickle cell trait have been found in autochthonous individuals, but this is very rare. Most of the studies of SCD prevalence in Spain are incomplete or focused on a few geographical regions. When screening has been carried out regardless of ethnic origin, overall haemoglobinopathy prevalence has varied from 0.14% to 0.94% and the estimated prevalence of SCD has varied from 0.001 (in Extremadura) to 0.03 (in Aragón). A registry for SCD maintained by the Spanish Society of Paediatric Haematology shows that in the last 4 years the prevalence of SCD has increased threefold. Only two Spanish Communities (Extremadura and Madrid) are running an official neonatal screening programme for SCD. Other Spanish Communities have finished local pilot studies and are expected to establish neonatal screening programmes shortly. Catalonia, the Spanish community with the highest African immigration flow and SCD genetic impact, has not yet established an official programme for SCD neonatal screening; screening currently depends on individual hospital policies and is restricted to at-risk ethnic groups. Studies performed so far suggest that universal screening should be recommended for regions with a high annual birth rate and SCD prevalence (Catalonia and Madrid, for example), with a targeted policy being restricted to regions with low annual birth rate and SCD prevalence.