Mutation load and human longevity.
Since paternal age at reproduction is considered to be the main factor determining human spontaneous mutation rate (Crow, J. (1993) Environ. Mol. Mutagenesis, 21, 122-129), the effect of paternal age on human longevity was studied on 8,518 adult persons (at age 30 and above) from European aristocratic families with well-known genealogy. The daughters born to old fathers (50-59 years) lose about 4.4 years of their life compared to daughters of young fathers (20-29 years) and these losses are highly statistically significant, while sons are not significantly affected. Since only daughters inherit the paternal X chromosome, this sex-specific decrease in daughters' longevity might indicate that human longevity genes (crucial, house-keeping genes) sensitive to mutational load might be located in this chromosome.