<prompt> Alpo syndrome is noted because of defect in what type of collagenCollagen type ICollagen type IVCollagen type IIICollagen type VII  <response>: Alpo syndrome is caused by mutations in COL4A3, COL4A4, and COL4A5, three of six human genes involved in basement membrane type IV collagen biosynthesis. ... Basement membranes are thin, sheet-like structures that separate and suppo cells in many tissues. Ref ganongs review of medical physiology 25e p540 