title: The parathyroid/pituitary variant of multiple endocrine neoplasia type 1 usually has causes other than p27Kip1 mutations.
abstract: BACKGROUND
  One variant of multiple endocrine neoplasia type 1 (MEN1) is defined by sporadic tumors of both the parathyroids and pituitary. The prevalence of identified MEN1 mutations in this variant is lower than in familial MEN1 (7% vs. 90%), suggesting different causes. Recently, one case of this variant had a germline mutation of p27(Kip1)/CDKN1B.
  
  
  OBJECTIVE
  The objective was to test p27 in germline DNA from cases with tumors of both the parathyroids and pituitary.
  
  
  METHODS
  Medical record review and sequence analysis in DNA were performed.
  
  
  METHODS
  This study involved an inpatient and outpatient referral program for cases of endocrine tumors.
  
  
  METHODS
  Sixteen index cases had sporadic tumors of two organs, both the parathyroids and the pituitary. There were 18 additional index cases with related features of familial tumors. Five subjects were normal controls. No case had an identified MEN1 mutation.
  
  
  METHODS
  Clinical status of endocrine tumors was tabulated. Sequencing of germline DNA from index cases and control cases for the p27 gene was performed by PCR.
  
  
  METHODS
  Endocrine tumor types and their expressions were measured, as were sequence changes in the p27 gene.
  
  
  RESULTS
  Tumor features were documented in index cases and families. One p27 germline single nucleotide change was identified. This predicted a silent substitution of Thr142Thr. Furthermore, there was a normal prevalence of heterozygosity for a common p27 polymorphism, making a large p27 deletion unlikely in all or most of these cases.
  
  
  CONCLUSIONS
  The MEN1 variant with sporadic parathyroid tumors, sporadic pituitary tumor, and no identified MEN1 mutation is usually not caused by p27 germline mutations. It is usually caused by as yet unknown process(es).
authors.affiliation: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1802, USA. ozawaa@niddk.nih.gov
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ozawa
authors.forename: Sunita K
authors.initials: SK
authors.lastname: Agarwal
authors.forename: Carmen M
authors.initials: CM
authors.lastname: Mateo
authors.forename: A Lee
authors.initials: AL
authors.lastname: Burns
authors.forename: Terri S
authors.initials: TS
authors.lastname: Rice
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Kennedy
authors.forename: Caitlin M
authors.initials: CM
authors.lastname: Quigley
authors.forename: William F
authors.initials: WF
authors.lastname: Simonds
authors.forename: Lee S
authors.initials: LS
authors.lastname: Weinstein
authors.forename: Settara C
authors.initials: SC
authors.lastname: Chandrasekharappa
authors.forename: Francis S
authors.initials: FS
authors.lastname: Collins
authors.forename: Allen M
authors.initials: AM
authors.lastname: Spiegel
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Marx
mesh_terms: D000328:Adult; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D018095:Germ-Line Mutation / Q000235:genetics; D006728:Hormones / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D018761:Multiple Endocrine Neoplasia Type 1 / Q000235:genetics*; D010282:Parathyroid Neoplasms / Q000235:genetics* / Q000473:pathology; D010911:Pituitary Neoplasms / Q000235:genetics* / Q000473:pathology; D011110:Polymorphism, Genetic / Q000235:genetics
chemical_list: D004273:DNA, Neoplasm; D006728:Hormones; D050760:Cyclin-Dependent Kinase Inhibitor p27