[Primary hyperparathyroidism. Concept, classification and symptomatology].

Primary hyperparathyroidism is a chronic, multi-system disease due to an overproduction of PTH from adenoma, hyperplasia or carcinoma of the parathyroid. Classical disease type classification consisted of bone type, kidney type and latent or chemical type. Though a longer course is usually associated with more severe involvement of especially the skeletal system and larger tumor size, the progression of the disease is not always uniform. Rapid tumor growth may be associated with shorter course and more extensive involvement. The role of PRAD1, a DNA sequence near the PTH gene on chromosome 11 possibly related to tumor growth, should further be investigated with reference to the disease types and courses of the disease.