[Mutation by deletion-insertion in BRCA-1 gene in three unrelated French breast/ovarian cancer families: possible implication of a mobile element].
A new type of mutation by deletion-insertion in BRCA-1 gene is found in three unrelated French breast/ovarian cancer families. Surprisingly, deletion and insertion occurred at the same nucleotide position at the end of exon 11 (3958del5ins4), thus generating a truncated protein. This original mutation consists in a deletion of 5 bp (CTCAG) and in an insertion of 4 different bp (AGGC). Here, we proposed two hypothesis to explain this phenomenom. The first hypothesis is the formation of a hairpin stem-loop structure comprising the mutational site and the sequence corresponding to the duplication insertion 2 nucleotides before the mutation. The second hypothesis, more speculative, consists in an abortive integration of a human mobile element as a human transposon (tigger 1) which involved a deletion of 5 bp during its excision and an insertion of 4 bases corresponding to the 5' extremity of the transposon.
Presneau
N
N
Laboratoire d'oncologie moléculaire, Inserm CRI 9502 & EA 2145, Centre Jean-Perrin, BP 392, 58, rue Montalembert, 63011 Clermont-Ferrand Cedex 1, France.
Laplace-Marieze
V
V
Sylvain
V
V
Lortholary
A
A
Hardouin
A
A
Bernard-Gallon
D
D
Bignon
Y J
YJ
D000328:Adult; D001943:Breast Neoplasms / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D019398:Genes, BRCA1 / Q000235:genetics*; D018095:Germ-Line Mutation / Q000235:genetics*; D006801:Humans; D020071:Interspersed Repetitive Sequences / Q000235:genetics*; D008875:Middle Aged; D016254:Mutagenesis, Insertional / Q000235:genetics*; D010051:Ovarian Neoplasms / Q000235:genetics*