[Clinical aspects of thalassemia (or microcythemia)].

The thalassaemias are genetic syndromes brought about by a low or nil synthesis of one or more of the main globinic chains and by consequent imbalance of the normal ratio between alpha and non-alpha chains. Three basic pictures can be distinguished: (1) microcythemia or thalassaemia minima, the expression of heterozygosis for one microcythemic gene, which includes beta, delta beta and alpha microcythemias. Subjects are healthy but very often pale and asthenic, (2) intermediate thalassaemia, very similar to thalassaemia major, though a less severe disease. It is the expression of the presence of microythemic geness which results in a globin synthesis imbalance less marked than that of the thalassaemia major. The patients are frankly anemic and more or less pronounced hyperhemolysis (but they only need sporadic transfusions, usually at adult age), and present splenomegaly often of a considerable extent and hepatomegaly. Their physical growth and reproductive capacity are normal or nearly so and they attain the fifth or sixth decade of life. Two varieties of this syndrome have been identified, namely beta-intermediate thalassaemias (or Rietti-Greppi-Micheli's disease or also constitutional microcythemic anemia) and alpha-intermediate thalassaemias (or Hb H disease); (3) thalassaemia major or Cooley's anemia or Mediterranean anemia, the expression of homozygosis for severe genes of microcythemia which results in a marked globin synthesis imbalance; this is a so severe disease that not treated patients usually die when they are three-four years old. Nowadays, however, prognosis, clinical course and life expectancy of these patients are considerably improved so that they usually attain the third decade of age in relatively fair conditions. There are available three fundamental therapeutic actions: blood transfusions carried out at very short intervals; splenectomy which allows to reduce the rhythm of the blood transfusion regimen; the iron chelating therapy which delays the onset of the iron overloading in the organism. Finally, it is possible the prevention of this disease by preventing the procreation between microcythemics and by prenatal identification of Cooley's foetuses followed by thier selective abortion.