A MULTIDISCIPLINARY study of pairs of monozygotic twins in which one has displayed schizophrenic symptomatology and the other has not is being conducted at the Clinical Center, National Institute of Mental Health (NIMH), Bethesda, Md.1-3 Investigation includes psychiatric, Psychologic, physiologic, and biochemical variables which are studied in each of the monozygotic (MZ) twins and both biologic parents. Previous papers have reported a number of the psychiatric and psychologic findings. This paper focuses on some of the biologic variables.
Frohman et al4,5 have reported a series of studies which suggested that individuals with a diagnosis of schizophrenia, as compared with nonschizophrenic controls, had a serum factor which produced higher lactate-pyruvate (L/P) ratios in an incubated chicken erythrocyte preparation. The work of Fessel et al6,7 indicated that psychotics, especially schizophrenics, had higher serum levels of S19 macroglobulins as compared to control subjects. Friedhoff and