ABSTRACT
Abdominal aortic aneurysm (AAA) is a multifactorial condition. The transforming growth factor beta (TGF-beta) pathway regulates vascular remodeling and mutations in its receptor genes, TGFBR1 and TGFBR2, cause syndromes with thoracic aortic aneurysm (TAA). The TGF-beta pathway may be involved in aneurysm development in general. We performed an association study by analyzing all the common genetic variants in TGFBR1 and TGFBR2 using tag single nucleotide polymorphisms (SNPs) in a Dutch AAA case-control population in a two-stage genotyping approach. In stage 1, analyzing 376 cases and 648 controls, three of the four TGFBR1 SNPs and nine of the 28 TGFBR2 SNPs had a P<0.07. Genotyping of these SNPs in an independent cohort of 360 cases and 376 controls in stage 2 confirmed association (P<0.05) for the same allele of one SNP in TGFBR1 and two SNPs in TGFBR2. Joint analysis of the 736 cases and 1024 controls showed statistically significant associations of these SNPs, which sustained after proper correction for multiple testing (TGFBR1 rs1626340 OR 1.32 95% CI 1.11-1.56 P=0.001 and TGFBR2 rs1036095 OR 1.32 95% CI 1.12-1.54 P=0.001 and rs4522809 OR 1.28 95% CI 1.12-1.46 P=0.0004). We conclude that genetic variations in TGFBR1 and TGFBR2 associate with AAA in the Dutch population. This suggests that AAA may develop partly by similar defects as TAA, which in the future may provide novel therapeutic options.
Subject(s)
Aortic Aneurysm, Abdominal/genetics , Polymorphism, Single Nucleotide , Protein Serine-Threonine Kinases/genetics , Receptors, Transforming Growth Factor beta/genetics , Aged , Aged, 80 and over , Aortic Aneurysm, Abdominal/surgery , Female , Gene Frequency , Humans , Male , Middle Aged , Netherlands , Receptor, Transforming Growth Factor-beta Type I , Receptor, Transforming Growth Factor-beta Type II , White People/geneticsABSTRACT
BACKGROUND AND PURPOSE: The 19q13.3 locus for intracranial aneurysms (IA) partly overlaps with the 19q13 locus for abdominal aortic aneurysms (AAA). A common genetic risk factor located in this locus for the two aneurysm types seems plausible. The transforming growth factor beta (TGF-beta) signalling pathway plays a role in aortic aneurysms but may also play a role in aneurysms in general. In the combined region of the 19q13 loci for IA and AAA we identified two candidate genes that are both involved in the TGF-beta signalling pathway: hepsin (HPN) and the latent transforming growth factor beta-binding protein 4 (LTBP4). We hypothesised that single nucleotide polymorphisms (SNP) in the HPN and LTBP4 genes are associated with IA. METHODS: We analyzed all the common variations using tag SNP in the HPN and LTBP4 genes for association with IA in 390 patients and 642 controls in the Dutch population. Six tag SNP in the HPN gene and five tag SNP in the LTBP4 gene were genotyped. RESULTS: No differences in SNP frequency were observed for both the HPN and LTBP4 gene between patients and controls. CONCLUSION: Our findings suggest that variations in or near the HPN and LTBP4 genes do not play a role in the susceptibility to IA in the Dutch population.
