Hyperparathyroidism-jaw tumor syndrome arises through autosomal inheritance, and PHPTis the most prevalent feature; the syndrome can also involve ossifying fibromas ofthe jaw and maxilla and has a higher prevalence of parathyroid carcinoma than MEN1and MEN2A (approximately 15% of cases) (15). The gene discussed is RET; the disease is parathyroid gland carcinoma.