AceShowbiz - Rocker John Mellencamp's new granddaughter is having to undergo neurosurgery to treat a rare bone condition.

The singer's daughter, reality TV star Teddi Mellencamp, reveals her four-month-old baby, Dove, has been diagnosed with Lambdoid Craniosynostosis, which causes the premature fusion of bones towards the back of an infant's skull, potentially affecting the child's appearance and brain development.

As a result, the tot is booked to head into the operating room in late July (20).

"The Real Housewives of Beverly Hills" castmember shared the news on Instagram on Monday (06Jul20), admitting she was initially hesitant about making the news public.

"I was torn as to whether I should share this information, but as someone who tries to be as transparent as possible, and knowing I have a platform to reach others in similar situations, I would like to update you all," the mother-of-three captioned a close up snap of her daughter.

"Our sweet baby Dove was diagnosed with Lambdoid Craniosynostosis and has to undergo neurosurgery at the end of the month."

Mellencamp went on to detail the "very high success rate" with the procedure, after which Dove will spend about a week in hospital recovering, before returning home for two more weeks of recuperation.

"So although we are filled with nerves as neurosurgery sounds scary, we have our faith that she will be ok," she added.

"Please keep baby Dove in your prayers and if you have had a child with this same surgery, please let me know below, as I would love any additional insight and support. Sending (love) to you all."

The reality star and her husband Edwin Arroyave also share daughter Slate, seven, and five-year-old son Cruz.

Additionally, Arroyave has an older girl named Isabella from a previous relationship.