This is known as kidney hypoplasia (developmental defect), and may be inherited, or occur in children with no family history of kidney disease.

Most kidney stones are made up of calcium and oxalate. Information about the causes, symptoms and treatment of kidney stones can be found at The Kidney Stone Web Site, Kidney Stones, and other web sites. Kidney stones occur in men more than women, and may have a variety of causes including your diet, your family genes, and other factors.Doctors used to prescribe a low calcium diet for preventing kidney stones. This approach makes little sense if you understand how calcium is managed in the body. Calcium levels in the blood are kept pretty steady by balancing the absorption of calcium from diet and taking calcium from bones when needed. Changing the amount of calcium in the diet causes very little change in the blood level of calcium The kidney filters substances from the blood, so changing the dietary intake of calcium does not change the amount of calcium that is filtered by the kidneys.