The organization of elastic fibres differs between controls and subsets of patients with rectal prolapse, and their importance for maintaining the structural and functional integrity of the pelvic floor has been demonstrated in transgenic mice, with animals which have a null mutation in fibulin-5 (Fbln5(i/i)) developing prolapse.
Both FIB-5 mRNA expression and FIB-5 staining intensity was significantly decreased in USL from women with uterine prolapse compared to women without prolapse {[(FIB-5 mean +/- SD mRNA relative units) 0.07 +/- 0.02 vs. 0.26 +/- 0.20, P = 0.02] and [Intensity score, median (range), 0(0-2) vs. 3(2-3), P = 0.002]}.