PHPT has characteristic clinical signs and symptoms such as osteoporosis and pathological fractures, gastrointestinal disturbances, neuropsychiatric disorders, neuromuscular manifestations, and nephrolithiasis or nephrocalcinosis, eventually complicated with urinary infections and kidney failure, which can be attributed to elevated levels of serum calcium and parathyroid hormone (PTH). The gene discussed is PTH; the disease is kidney failure.