Paternal age effect mutations and selfish spermatogonial selection: causes and consequences for human disease

Area of Science:

• Genetics
• Reproductive Biology
• Oncology

Background:

• Advanced paternal age is linked to increased risks of congenital disorders and complex diseases.
• Mechanisms underlying this paternal age effect (PAE) are poorly understood.
• PAE disorders, such as Apert syndrome and Costello syndrome, serve as models for study.

Purpose of the Study:

• To investigate the molecular mechanisms behind advanced paternal age effects on offspring health.
• To elucidate the role of spermatogonial cell behavior and the RAS pathway in PAE.
• To understand the implications of these mechanisms for congenital disorders and complex diseases.

Main Methods:

• Direct quantification of PAE mutations in sperm and testes.
• Analysis of clonal expansion of mutations in spermatogonial cells.
• Investigation of the growth factor receptor-RAS signal transduction pathway.

Main Results:

• PAE mutations arise rarely but are positively selected and clonally expand in testes.
• This clonal expansion leads to enrichment of mutant sperm with increasing paternal age.
• The process resembles oncogenesis and can lead to testicular tumors in rare cases.

Conclusions:

• Dysregulation of spermatogonial cell behavior via the RAS pathway underlies the paternal age effect.
• Clonal expansion of PAE mutations explains increased risks for congenital disorders.
• These mechanisms may also contribute to complex diseases like neurocognitive disorders and cancer.