3 September 2008

Herpes Virus Transferred To Infants Via Parental DNA

by Kate Melville

Parents expect to pass on their eye or hair color to their children through their genes but new research from the University of Rochester Medical Center shows that some parents pass on the human herpes virus 6 (HHV-6) to their children because it is integrated into their chromosomes.

Reporting their findings in the journal Pediatrics, the scientists behind the discovery say that this is the first time a virus has been shown to become part of the human DNA and then get passed to subsequent generations. This unique mode of congenital infection may be occurring in as many as 1 of every 116 newborns and the long-term consequences for a child's development and immune system are unknown.

"At this point, we know very little about the implications of this type of infection, but the section of the chromosome into which the virus appears to integrate is important to the maintenance of normal immune function," said study author Caroline Breese Hall. "With further study, we hope to discern whether this type of infection affects children differently than children infected after birth."

"This is the first time a herpes virus has been recognized to integrate into the human genome. To think that it's actually a part of us - that's really fascinating," said co-researcher Mary Caserta. "This opens up a whole new realm of exploration."

Of 254 children enrolled in this study, those who had integrated HHV-6 had higher levels of virus in the body than those who were infected through the placenta. HHV-6 DNA was found in the hair of one parent of all children with integrated virus with available parental samples (18 mothers and 11 fathers), which means the children acquired the integrated infections through their mother's egg or father's sperm at conception. The virus's DNA was not found in hair samples of parents of children who were infected after birth.

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Source: University of Rochester Medical Center