All of the cystic diseases of kidney cause enlargement of kidney/renomegaly, except:

Nephronopthisis Kidneys are small, have contracted granular surfaces, show cysts in the medulla, at the coicomedullary junction. Children with juvenile nephronophthisis have extrarenal manifestations, which most often appear as retinal abnormalities, including retinitis pigmentosa, and even early-onset blindness in the most severe form