title: [A case report and pedigree study of a single point mutation in RET proto-oncogene and type 2B multiple endocrine neoplasia].
abstract: OBJECTIVE
  To determine the relationship between a single point mutation in RET proto-oncogene and the occurrence of multiple endocrine neoplasia type 2B (MEN-2B) in a Chinese pedigree.
  
  
  METHODS
  We used the methods of polymerase chain reaction (PCR), reverse transcriptase polymerase chain reaction (RT-PCR) and direct gene sequencing of PCR products by an automated DNA sequencer to scan the entire exon 16 of RET proto-oncogene in the tumor (c)DNA from one patient with MEN-2B and the leukocyte DNA from this patient and both of his parents.
  
  
  RESULTS
  We found the same mutation Met(ATG)-->Thr(ACG) at codon 918 in exon 16 of RET proto-oncogene in both the tumor (c)DNA and leukocyte DNA of the MEN-2B patient in the form of homozygous missense mutation, but there was no corresponding mutation in leukocytes DNA of his parents.
  
  
  CONCLUSIONS
  We propose that in Chinese population, the point mutation M918T is also associated with the onset of MEN-2B and this case of MEN-2B is sporadic. Thus it may provide a genetic basis for the early diagnosis and treatment of patients suffering from MEN-2B and their at-risk family members in Chinese population.
authors.affiliation: Department of Endocrinology, Ruijin Hospital, Shanghai Second Medical University, Shanghai 200025, China.
authors.forename: Yi-fei
authors.initials: YF
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Hong
authors.forename: Yong-ju
authors.initials: YJ
authors.lastname: Zhao
authors.forename: Huai-dong
authors.initials: HD
authors.lastname: Song
authors.forename: Xiu-ying
authors.initials: XY
authors.lastname: Yang
authors.forename: Guang
authors.initials: G
authors.lastname: Ning
authors.forename: Man-yin
authors.initials: MY
authors.lastname: Xu
authors.forename: Jia-lun
authors.initials: JL
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D006801:Humans; D008297:Male; D018814:Multiple Endocrine Neoplasia Type 2b / Q000235:genetics*; D010375:Pedigree; D017354:Point Mutation; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases