Early onset acromegaly associated with a novel deletion in CDKN1B 5′UTR region

Genetic alterations frequently are involved in the development of a pituitary adenoma in young age. We here characterize the functional role of a deletion in CDKN1B 5′-UTR region (c.-29_-26delAGAG) identified in an acromegalic patient that developed a growth hormone in pituitary adenoma during childhood. Our results show that the identified novel heterozygous deletion in the CDKN1B 5′-UTR region associates with a reduction in CDKN1B mRNA levels, a predicted altered secondary mRNA structure, and a reduced CDKN1B 5′-UTR transcriptional activity in vitro. The patient displayed loss of heterozygosity in the same CDKN1B 5′-UTR region at tissue level and the 5′UTR region containing the deleted sequence encompasses a GRE. These findings indicate that the identification of functional alterations of newly discovered genetic derangements need to be fully characterized and always correlated with the clinical manifestations.