[From gene to disease; from hemoglobin genes to thalassemia and sickle cell anemia].

Haemoglobinopathies are the commonest autosomal recessive diseases in men. Mutations on the alpha and beta genes clusters, located on chromosome 16 and 11 respectively, have been strongly selected in many populations by the increased chance of survival of carriers in areas infested with malaria tropica. Unfortunately many of these mutations in homozygous or compound heterozygous forms generate severe phenotypes such as sickle cell disease and beta-thalassaemia major. The population at risk for haemoglobinopathies is increasing in the industrialized areas of northern Europe. Without preventive measures a cumulative number of 1,000 severely affected patients can be expected in the Netherlands if information and carrier diagnostics are not efficiently offered at the GP level. A specialized laboratory for postnatal and prenatal diagnosis has been available in Leiden for more than 10 years now; however, couples at risk are only sporadically referred for counselling and/or prenatal diagnosis.