[Polymorphism in alkaline phosphatase (author's transl)].

1. In horizontal starch-gel electrophoresis placental extracts show an alkaline phosphatase polymorphism which - according to ROBSON and HARRIS - depends on the fetal genotype. Investigations carried out with a series of 73 placentas revealed 5 of the common 6 phenotypes. Their frequencies were in good accordance with the figures published by the English authors. However, there had been difficulties in typing because of obscrue realizing of the patterns. 2. Although there exists a polymorphism of the heart-stable alkaline phosphatase as observed in 66 serum samples from women at delivery, only four types could be distinguished which, however, could not be related to the placental patterns with any certainty. 3. In all but one of 66 samples of cord serum, investigated simultaneously, a single band only could be observed moving at a slower speed than the serum bands of adult pregnant and non-pregnant persons. This is in conformity with the results of the other investigators. 4. In 18 samples of unheated serum the amount of heat-labile alkaline phosphatase was unimportant and did not alter the features of the heat-stable portion of the enzyme. 5. Contrary to expectations, the alkaline phosphatase polymorphism has no medicolegal relevance.