Genetics of multiple endocrine neoplasia type 1 syndrome: what's new and what's old

<ns4:p>Despite its identification in 1997, the functions of the <ns4:italic>MEN1</ns4:italic> gene—the main gene underlying multiple endocrine neoplasia type 1 syndrome—are not yet fully understood. In addition, unlike the <ns4:italic>RET</ns4:italic>—MEN2 causative gene—no hot-spot mutational areas or genotype–phenotype correlations have been identified. More than 1,300 <ns4:italic>MEN1</ns4:italic> gene mutations have been reported and are mostly "private” (family specific). Even when mutations are shared at an intra- or inter-familial level, the spectrum of clinical presentation is highly variable, even in identical twins. Despite these inherent limitations for genetic counseling, identifying <ns4:italic>MEN1</ns4:italic> mutations in individual carriers offers them the opportunity to have lifelong clinical surveillance schemes aimed at revealing MEN1-associated tumors and lesions, dictates the timing and scope of surgical procedures, and facilitates specific mutation analysis of relatives to define presymptomatic carriers.</ns4:p>