[A genetic analysis of neurological symptoms in schizophrenic families]

To investigate an accumulation of certain neurological signs in patients with schizophrenia and their relatives and to estimate heritability of neurological abnormalities, 95 patients, 169 relatives and 35 healthy subjects have been studied using standardized clinical neurological examination. Neurological abnormalities in patients and their relatives did not form a constant and localized pattern and exerted an influence on various functions. A frequency of each symptom, with an exception of autonomic ones, was low both in families and controls. A total neurological index as well as generalized indices of 2 categories of most frequent disorders--motor and autonomic--did not reveal a significant genetic determination. Therefore, neurological symptoms detected during the clinical neurological examination of the relatives may be considered as markers of genetic risk for schizophrenia.