Challenges in the differential diagnosis of multiple endocrine neoplasia syndrome type 1 with isolated family hyperparathyroidism

Abstract

Multiple endocrine neoplasia type 1 (MEN-1) is the most common cause of the hereditary type of primary hyperparathyroidism (PHPT). If a family type of PHPT is suspected, a dynamic monitoring of patients and their close relatives should be carried out throughout their lives. We present a clinical case of a family in which four members of a pedigree were diagnosed with familial isolated hyperparathyroidism (FIHP). The diagnosis was changed to MEN-1, because it appeared that one of the patients had pancreatic neuroendocrine tumor. Molecular genetic study of MEN1 by direct by means of Sanger sequencing revealed that six family members had a new heterozygous mutation in exon 9: s. 1252 G> T p. D418Y.