Clinical aspects of hyperparathyroidism in Japanese multiple endocrine neoplasia type 1

We describe here the clinical aspects of hyperparathyroidism (HP) in Japane se multiple endocrine neoplasia type 1 (MEN 1). The total number of MEN 1 p atients was 37, and they originated from ten unrelated Japanese families. N ine of the ten families were proven to have heterozygous germline mutations of the MEN 1 gene. The incidence of HP, pituitary tumors, and pancreatic t umors in 37 MEN 1 patients was 91.9%, 32.4%, and 45.9%, respectively. The a ge-related penetrances of HP were 50%, 79%, 84%, by 20, 30, and 40 years of age, respectively. Of these MEN 1 patients, we used 28 individuals, diagno sed with KP at our hospitals, to study the clinical aspects of MEN 1-associ ated HP. The mean age was 40 years, and the mean was much lower in the spor adic (non-MEN 1) HP patients. The mean levels of calcium, phosphate, and in tact PTH were 10.8 mg/dL, 2.3 mg/dL, and 178.0 pg/mL, respectively, and the se were not different from those of sporadic HP patients. The levels of int act PTH were positively correlated with age, suggesting that HP may be prog ressive with time in MEN 1. The percentage of symptomatic HP was 36% in MEN 1, whereas it was 55% in sporadic HP patients. Although histopathological findings revealed that all four parathyroid glands were involved in hyperpl asia, imaging studies showed an enlargment of only the single parathyroid g land in most patients. The combination of total parathyroidectomy and autop lantation succeeding in improving HP in MEN 1. (C) 2000 Editions scientifiq ues et medicales Elsevier SAS.