I know two people with one kidney each. The mother passed it to her son. The son’s in utero ultrasound showed two kidneys but ultimately one of them developed cysts and then degraded away to nothing. I believe it was called poly cystic kidney disease but don’t quote that one for sure. The reason for it appears to be unknown. Could be related to a mild metabolic acidosis or an imbalance in acids and bases from the mother with one kidney and it impacted the developing fetus. Not sure if your mom has two and you have one, more discussion with your mom about her well-being during that time could maybe be helpful.
I would pay attention to your acid load (you could track your urine ph for a little while perhaps, although it’s not entirely indicative. I believe Peat wasn’t a huge fan). You’d maybe want to include higher ratio of alkali salts (K, NCHO3, Ca) and Mg in the form of mag bicarbonate to the acids including NaCl and not go too overboard with high amounts of animal proteins or at least as you get older and again ensuring balance
Cheers