This is the first report of positive CDKN1B mutation analysis in a male subject and also the first description of recurrent hyperparathyroidism in MEN4.
We report the identification of a heterozygous GAGA deletion in the 5'-UTR of CDKN1B, NM_004064.3:c.-32_-29del, in a patient affected by gastric carcinoid tumor and hyperparathyroidism.
Inactivating mutations of CDKN1B, encoding the p27 cyclin-dependent kinase inhibitor, were reported to cause hyperparathyroidism in a multiple endocrine neoplasia type 1-like syndrome.