[Role of genetic factors in increasing the serum lactate dehydrogenase activity of schizophrenic patients].

To elucidate the role of genetic factors in the increase of the blood serum LDH activity in schizophrenics', there have been studied 103 patients, 97 first degree nonpsychotic relatives, 58 healthy people and 32 pairs of likesex MZ and DZ twins (schizophrenics and normals). A correlation between the enzyme activity in the probands and their relatives is marked. With the aid of a quantitative estimation of the degree of genetic determination of the studied characteristic and special and twin methods the authors obtained the results fitting the hypothesis of additive polygenic inheritance with threshold manifestation.