A novel germline mutation of multiple endocrine neoplasia type 1 (MEN1) gene in a Japanese MEN1 patient and her daughter

Familial multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominan t inherited disorder characterized by tumors of the parathyroid, anterior p ituitary and gastro-entero-pancreatic endocrine tissues. The MEN1 gene has recently been cloned and its germline mutations have been considered to pla y an important role in the tumorigenesis of MEN1. We analyzed a Japanese ME N1 patient and her daughter for germline mutations of the MEN1 gene. The pr oband (60 y.o.) had primary hyperparathyroidism (PHP) and gastrinoma, and h er daughter (30 y.o.) had prolactinoma. Clinical examinations revealed no e vidence of PHP in the daughter. We identified a novel heterozygous germline mutation (712 A del) at codon 201 in exon 3 of the MEN1 gene in the proban d. Restriction digestion analysis revealed the same mutation pattern in her daughter. These findings suggest that this family has familial MEN1 includ ing a rare case of MEN1 with a single lesion of the pituitary. Genetic exam inations are useful as diagnostic tools for any rare or variant case of fam ilial MEN1.