Menin mutations in the diagnosis and prediction of multiple endocrine neoplasia type 1.
BACKGROUND
Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by the development of multiple endocrine adenomas, typically in the pancreas, anterior pituitary, and parathyroid glands. The disease is associated with germ-line mutations of the menin gene, a putative tumor-suppressor gene located on human chromosome 11q13.


METHODS
To facilitate the diagnosis and prediction of MEN1 in patients and their relatives, we developed a molecular two-step strategy to screen for menin gene mutations. DNA fragments covering the entire menin coding sequence are generated from patient cDNA by polymerase reaction (PCR) and subsequently analyzed by single-strand conformational polymorphism electrophoresis (SSCP). Fragments with aberrant SSCP migration are DNA-sequenced to directly characterize menin mutations. In a second diagnostic step, genomic DNA of healthy relatives of the corresponding MEN1 index patient is analyzed by PCR, with only the specific exon amplified harboring the family-specific mutation. Mutation-specific restriction enzyme digestion of this PCR product finally allows the identification of mutation carriers through pathological restriction fragment patterns.


RESULTS
Using this approach, we identified an in-frame deletion mutation (delta Tyr Met) located in menin exon 4 (codon 227-228) that co-segregates with the disease phenotype in a large MEN1 family from Southern Germany.


CONCLUSIONS
It is likely that the direct molecular analysis of menin gene mutations will replace the genetic and biochemical screening tests currently used in the clinical management of MEN1 families. In addition, these studies may provide clues to the tumor biology of both sporadic and MEN1-associated endocrine adenomas.
Karges
W
W
Division of Endocrinology, Department of Internal Medicine, University of Ulm, Germany.
Ludwig
L
L
Kessler
H
H
Wissmann
A
A
Wagner
P K
PK
Boehm
B O
BO
D000328:Adult; D002869:Chromosome Aberrations / Q000235:genetics; D002872:Chromosome Deletion; D025063:Chromosome Disorders; D002880:Chromosomes, Human, Pair 11; D004252:DNA Mutational Analysis; D005260:Female; D005799:Genes, Dominant / Q000235:genetics; D006580:Genetic Carrier Screening; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D018761:Multiple Endocrine Neoplasia Type 1 / Q000175:diagnosis / Q000235:genetics* / Q000517:prevention & control; D009154:Mutation / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics*; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins
C105373:MEN1 protein, human; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins