Baby monkey offers hope child cancer patients can start a family
A monkey left infertile after undergoing chemotherapy as a juvenile has fathered an infant because scientists froze its testicular tissue before treatment, then re-grew it after the animal reached adulthood.
It is the first time that the technique has been proven to work in primates and offers hope that childhood cancer patients can preserve their fertility.
Adult cancer patients have the option of banking their sperm but for boys their reproductive tissue does not start producing sperm until puberty, so there is nothing to save.
As a result, one in three childhood cancer survivors suffers infertility from harsh cancer treatment.
Scientists at the University of Pittsburgh cryopreserved the immature testicular tissue of five young rhesus monkeys that had not undergone puberty, before giving them chemotherapy.
They later thawed and transplanted the pieces of tissue under the skin of the same animal, and when they entered puberty, eight to 12 months later, the grafts were removed and sperm was found to be present.
The sperm was then used to fertilise 138 eggs, 41pc of which developed into early stage embryos and 11 were transferred into females. Last April, a female was born from the study and named Grady which has remained healthy.
"With Grady's birth, we were able to show proof-of-principle that we can cryopreserve pre-pubertal testicular tissue, and later use it to restore fertility as an adult," said author Dr Adetunji Fayomi, of Pittsburgh's School of Medicine.
"Previous research in non-human primates has demonstrated sperm could be produced from transplants of frozen prepubertal testicular tissue, but the ability to produce a healthy live offspring - the gold standard of any reproductive technology - has not been achieved until now."
Senior author Dr Kyle Orwig added: "This advance is an important step towards offering young cancer patients around the world a chance at having a family in the future."