EFEMP2 and triple-A syndrome: Moreover, a study investigating 31 familial AAA patients and 12 sporadic AAA patients identified forty-seven variants in the genes encoding collagen, type III α1 (COL3A1), EGF-containing fibulin-like extracellular matrix protein 2 (EFEMP2), fibrillin 1 (FBN1), MYH11, myosin light chain kinase (MYLK), transforming growth factor-β2 (TGFB2), transforming growth factor-β receptor type I (TGFBR1), and transforming growth factor-β receptor type II (TGFBR2), suggesting that additional genes are involved in the pathogenesis of AAA [96].