Tamra Judge's granddaughter, Ava Ryan, was reportedly born with just one kidney.

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In a recent post on Instagram, the Real Housewives of Orange County star's daughter-in-law, Sarah Rodriguez, revealed the shocking news of her daughter's condition, claiming the child had two kidneys before birth, but after birth, one had mysteriously disappeared.

“She was simply born with one kidney. She is healthy and is being monitored by doctors every few months," a source explained to Radar Online of Ava's health.

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According to F. Perry Wilson, a nephrologist and assistant professor of nephrology at Yale School of Medicine, the condition is extremely rare.

“Documentation of two kidneys with one going away is super super super unusual,” he explained. “It’s not easy to get great pictures when the kid is in the uterus. Often times, maybe you think you see a kidney and then when the baby is born, you can get a much better picture and you see that there’s not a kidney there. So that’s probably the most likely explanation. Kidneys don’t really disappear without a trace, except in extraordinarily rare circumstances.”

While the odd incident with Ava may come as alarming to most, Wilson claimed her health status is generally not life-threatening.

Tamra Judge will return to Bravo for The Real Housewives of Orange County season 11 later this year.