The nuclear envelope is a thin membrane that surrounds the genetic material in eukaryotic cells. It consists of a double layer of lipids, separating the nucleus content, principally DNA, from the surrounding cell cytoplasm.
The outer part of the nuclear envelope membrane is rough endoplasmic reticulum spotted as it is with ribosomes. The inner part consists of flat membrane proteins eg Emerin which are linked to the nuclear lamina and mutations in Lamins A and B.
The nuclear envelope is perforated with pores which enable the transport of proteins and RNA between the nucleus and cytoplasm. The inner and outer membranes conjoin at each nuclear pore site.