Prevention of thalassemia.

Prevention of thalassemia and hemoglobinopathies is the only solution to efficiently reduce the huge medical, social and economic impact of these diseases in countries where they occur in high frequencies. In Greece, a serious effort has been undertaken towards this goal over the last years. Prevention is carried out at various levels: ample public education, easy provision of the necessary laboratory tests for carrier identification and thorough counseling of the couples at risk. Availability of prenatal diagnosis has contributed significantly to the acceptance by the public of various screening programmes. To date, the experience of the Greek group for prenatal diagnosis totals 1088 cases (June 1977 to December 1982). The number of couples at risk seeking the test prior to having any children is steadily increasing (prospective counseling). The efficacy of the overall prevention programme in Greece is reflected by the fact that the number of babies with thalassemia major admitted for transfusion to the major Units of the country has decreased substantially in the last years. Routine method used for prenatal diagnosis is biosynthesis of hemoglobin in samples of placental blood drawn by fetoscopy. With increasing experience the procedure now is safe (less than 1% of obstetrical complications in the last year) and the prediction accurate (no false diagnoses in the recent years). However, it is anticipated that the conventional method will soon be replaced by studies of amniotic cell DNA, a procedure both safer and less traumatic, or by studies of trophoblast DNA, which will allow prenatal diagnosis at an earlier stage of pregnancy.