COL4A5 and Alport syndrome: In Alport syndrome mutations, Col3a3, Col4a4, and Col4a5 cause thinning of both the ILM/NFL and the RPE Bruch's basement membrane.70 It is known that Col 4a3, Cola4, Col a5, and Cola6 maintain the mechanical stability of mature basal lamina, including ILM at stages of increasing mechanical demands.71 Both basement membrane and RS1 are integral components of the ECM and provide essential physical scaffolding for the cellular constituents and initiate crucial biochemical and biomechanical forces across length scales in the retina required for morphogenesis and homeostasis.