Introduction: The genetic causes of development of multiple endocrine neoplasia type 1 (MEN-1) phenocopies remain largely unknown.
Aim of the study: To evaluate the role of genes associated with familial primary hyperparathyroidism (PHPT) in the development of MEN-1 phenocopies with the combination of PHPT and pituitary adenomas (PA).
Materials and methods: 20 patients (19 females and 1 male) were included in the study. All patients had biochemically confirmed PHPT in combination with PA of different types of secretion: 15 GH-secreting, 3 ACTH-secreting, 1 PRL-secreting, 1 non-functioning PA. Median age at the time of inclusion was 61 years [Q25-Q75;min-max:5766.5;5479], median age at the time of PHPT diagnosis was 57 years [Q25-Q75;min-max:5462;5172], median age at the time of PA diagnosis was 47 years [Q25-Q75;min-max:40.557.5;2161]. Five patients had mild PHPT, 15 manifest PHPT (though it was difficult to assess the role of PHPT in osteoporosis development due to concomitant menopause and Cushing disease in some cases). Imaging techniques revealed: in 15 patients solitary parathyroid tumour, in 2 patients two parathyroid tumours, in 3 patients parathyroid tumours were not visualized. In the majority (n=16) of patients PA was the first manifestation, only in 4 patients PHPT was diagnosed before PA. In all patients no MEN1 mutations were identified by Sanger sequencing, confirming diagnosis of MEN-1 phenocopy. Next-generation sequencing of a custom-designed Ion AmpliSeqTM panel of genes associated with familial PHPT (MEN1, CASR, CDC73, CDKN1A, CDKN1B, CDKN1C, CDKN2A, CDKN2C, CDKN2D) using semiconductor sequencer PGMTM Ion Torrent (Thermo Fisher Scientific, USA) was performed. ANNOVAR was used for variant annotation.
Results: No pathogenic or likely pathogenic variants in the abovementioned genes were identified.
Conclusion: Mutations in the genes associated with familial PHPT are unlikely to have any role in the development of MEN-1 phenocopies with combination of PHPT and PA.
20 - 23 May 2017
European Society of Endocrinology