Retinitis Pigmentosa 56, also known as rp56, is related to cornelia de lange syndrome 4 with or without midline brain defects and cornelia de lange syndrome. An important gene associated with Retinitis Pigmentosa 56 is IMPG2 (Interphotoreceptor Matrix Proteoglycan 2). Affiliated tissues include retina and eye, and related phenotypes are reduced visual acuity and visual field defect