Sydney, Sep 2 (IANS): Children fathered by men aged 50 years or above face a higher risk of autism or schizophrenia due to a repetition or deletion of their genes, says a research.

Queensland Brain Institute (QBI) researchers have pinpointed a genetic mechanism that may explain why such children are more likely to develop such neuro-degenerative diseases (loss of neurons).

Using advanced screening methods, they compared the offsprings of three-month-old male mice with those fathered by less sprightly 14-16 month old fathers, the journal Translational Psychiatry reports.

"This study provides the first evidence of the biological mechanism that may be responsible," he explains.

They found that mice fathered by older dads had an increased number of new copy number variants (CNVs) in their DNA, according to Queensland Institute statement.

CNVs can either result in the missing of genes or can make more copies of them. So CNVs can delete or repeat whole 'paragraphs' of genetic code.

These results offered the first experimental demonstration that the offspring of older males have an increased risk of new CNVs, according to QBI professor John McGrath.

He conducted the research with Emma Whitelaw (Queensland Institute), and QBI's Claire Foldi and Traute Flatscher-Bader.