Lesions formed by bone resorption and replacement with immature bone that lacks proper structure and mineralization, results from primary or secondary hyperparathyroidism; secondary hyperparathyroidism is more common and is due to renal disease, elevated parathyroid hormone, and/or calcium and phosphorus mineral imbalance; bilateral enlargement of the cranium and mandible are especially noted with this condition. This evidence concerns the gene PTH and secondary hyperparathyroidism.