title: BAK1 gene variation and abdominal aortic aneurysms.
abstract: We sought to examine the role of genetics in the multifactorial disease, abdominal aortic aneurysm (AAA), by studying sequence variation in the BAK1 gene (BAK1) that codes for an apoptotic-promoting protein, as chronic apoptosis activation has been linked to AAA development and progression. BAK1 abdominal aorta cDNA from AAA patients and nondiseased individuals were compared with each other, as well as to the BAK1 genomic sequence obtained from matching blood samples. We found specific BAK1 single nucleotide polymorphism (SNP) containing alleles in both aneurysmic (31 cases) and healthy aortic tissue (5 cases) without seeing them in the matching blood samples. These same BAK1 SNPs have been reported, although rarely (average frequency <0.06%), in reference BAK1 DNA sequences. Based on this and other similar observations, we propose a novel hypothesis postulating that multiple variants of genes may preexist in "minority" forms within specific nondiseased tissues and be selected for, when intra- and/or extracellular conditions change. Therefore, the fact that different BAK1 variants can exist in both diseased and nondiseased AA tissues compared to matching blood samples, together with the rare occurrence of these same SNPs in reference sequences, suggests that selection may be a significant factor in AAA ontogeny.
authors.affiliation: Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montréal, Québec, Canada. bruce.gottlieb@mcgill.ca
authors.forename: Bruce
authors.initials: B
authors.lastname: Gottlieb
authors.forename: Lorraine E
authors.initials: LE
authors.lastname: Chalifour
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mitmaker
authors.forename: Nathan
authors.initials: N
authors.lastname: Sheiner
authors.forename: Daniel
authors.initials: D
authors.lastname: Obrand
authors.forename: Cherrie
authors.initials: C
authors.lastname: Abraham
authors.forename: Melissa
authors.initials: M
authors.lastname: Meilleur
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sugahara
authors.forename: Ghassan
authors.initials: G
authors.lastname: Bkaily
authors.forename: Morris
authors.initials: M
authors.lastname: Schweitzer
mesh_terms: D000483:Alleles; D017544:Aortic Aneurysm, Abdominal / Q000235:genetics*; D016022:Case-Control Studies; D004252:DNA Mutational Analysis; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D013312:Stress, Physiological / Q000235:genetics; D050998:bcl-2 Homologous Antagonist-Killer Protein / Q000235:genetics*
chemical_list: C494772:BAK1 protein, human; D050998:bcl-2 Homologous Antagonist-Killer Protein