FBN1 and aortic aneurysm: Recently, a missense mutation in TGFβR2 identical to the one found in MFS patients who tested negative for mutation in FBN1 was found in a patient with BAV and aortic aneurysm [37] but an earlier study found no mutation in either TGFBR1 or TGFBR2 in patients with isolated BAV.