Novel mutation 928G>C ofMEN1gene in a familial multiple endocrine neoplasia type 1 case (MEN1) with co-existence of insulinoma and glucagonoma1名同时合并胰岛素瘤与胰高血糖素瘤的家族性多发性内分泌腺瘤1型（MEN1）患者的MEN1基因出现了新的928G>C突变