Family screening in multiple endocrine neoplasia type 1 (MEN 1).

Multiple endocrine neoplasia type 1 is an autosomal dominantly inherited disorder predisposing to development of neoplastic lesions in the parathyroid glands, the neuro-endocrine pancreas-duodenum and the anterior pituitary. The genetic defect was mapped to the centromeric region of the long arm of chromosome 11, based on studies of somatic deletions in MEN 1-associated tumours and linkage analysis in affected families. Combined family and tumour analyses have shown that tumourigenesis in MEN 1 involves loss of the wild type chromosome, indicating that the putative MEN 1 gene is a tumour suppressor gene. Based on results from linkage analysis in more than 40 MEN 1 families, presymptomatic testing for MEN 1 using DNA polymorphisms can now be performed with high accuracy. Hence, biochemical screening programmes can focus on individuals at risk, in order to identify early signs of tumour development.