A novel deletion of theMEN1gene in a large family of multiple endocrine neoplasia type 1 (MEN1) with aggressive phenotype

Gene copy number analysis by MLPA should be considered in patients with negative conventional mutation screening. Although large MEN1 deletion causes MEN1, disruption of imprinted CDKN1C/p57KIP2 and IGF-2 gene expression may contribute to tumour progression and aggressive phenotype.