[A study on a possible association between chromosome loss and impairment of mental functioning in the aged (author's...

Chromosome examinations in 40 (16 males and 24 females) aged subjects were compared with those of 30 (15 males and 15 females) young subjects. For the aged, all available data gathered from detailed medical examinations and laboratory findings were reviewed to exclude persons who were classified as with cerebral arteriosclerosis. The diagnosis of organic brain syndrome was based on psychiatric evaluation and the score on the Graham-Kendall Memory-For-Designs test was obtained. These two assesssments have been used as the basis for the comparison between mental functioning and chromosomal changes (aneuploidy). The percentage of peripheral leukocytes which showed loss of one or more chromosomes (hypodiploid cells) was not substantially larger among the aged than among the young men; yet aged men showed a significant loss of G-group chromosomes (including the Y chromosome). By contrast, a significantly higher proportion of hypodiploid cells was for the elderly women when compared with young women. Most of the missing chromosomes belonged to the C-group chromosomes (including the X chromosomes). Further, an excess of hypodiploid cells among the aged females who had organic brain syndrome was confirmed. A similar association was demonstrated between hypodiploidy and the score on the Memory-For-Designs test. For the aged males, however, there was no remarkable relationship between frequency of hypodiploid cells and either diagnosis of organic brain syndrome or Graham-Kendall score. Thus, the data provide confirmation for an association between mental status and chromosome loss at least with aged females. Possible explanations were made on the above discrepancy appeared between sexes as well as on biological and genetic factors between mental functioning and chromosomal changes in the process of aging.