Color vision anomalies and the genetics of aging.

In order to rest whether mutations giving rise to color vision deficiencies are more frequently inherited from older fathers, an exhaustive screening of births in the Namur region has allowed to isolate a sample of 225 descen ding sons of maternal grandfathers who were older than 45 years at their da ughter's birth. The incidence of color vision defects was compared between this set of cases and three control groups totalling 959 boys from independ ent families. While these comparisons were not conclusive, we propose new h ypotheses concerning the population dynamics of color Vision deficiencies. Neomutations in X-linked pigment genes may be a marker of the overall genet ic load borne by the X chromosome. Selection against such loaded X chromoso mes may occur in the second generation. either in the course of embryogenes is, or during female gametogenesis. The future assessment of these novel hy potheses relies on the arbitration of molecular genetics. (C) 2001 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.