Twenty-one cases of familial hereditary Alzheimer's disease and 17 sporadic cases were under observation. The probands' clinical status was assessed during a number of years in accordance with the standard method (based on a unified map). The clinical parameters (dementia structure, intensity of neurologic disorders, and so forth) were correlated at the identical disease stages. The differences in the character of the initial disease manifestations and the tempo of its progression as well as definite differences in the dementia structure at the pronounced stage and in the final stage allowed a conclusion about the ++clinico-genetic heterogeneity of the hereditary and sporadic cases of Alzheimer's disease.