Reproductive functions, fertility and genetic risks of ageing men

The changes of reproductive functions, fertility and genetic risks of agein g females have been investigated relatively intensively. The slate of knowl edge about endocrine and reproductive changes in ageing men as well as poss ible age-related paternal genetic risks lags far behind. In general serum t estosterone levels decrease with increasing age. In ageing men testis morph ology and semen production can be absolutely normal. However, in some teste s degenerative forms of germ cells can be observed. Fertility may be mainta ined up to a very high age. The genetic quality of sperm produced by older men may be reduced for several reasons, among which age-related increases i n germ cell mutations, impairment of DNA-repair mechanisms and apoptotic pr ocesses are the most likely The incidence of several autosomal dominant dis eases, such as achondroplasia; polyposis coli, Marfan syndrome; Apert syndr ome or basal cell, naevi is associated with advanced paternal age, whereas there is no clear evidence for a paternal effect on structural or numeric c hromosome anomalies. Hence even if offspring of older men have a slightly i ncreased incidence of certain genetic diseases: the individual risk of such a new disease must be considered as extremely small, as the incidence of t hese diseases is very low.