The hypodermis is the innermost and thickest layer of the skin. It invaginates into the dermis and is attached to the latter, immediately above it, by collagen and elastin fibres. It is essentially composed of a type of cells specialised in accumulating and storing fats, known as adipocytes.
Fatal familial insomnia Fatal familial insomnia (FFI) is a very rare, autosomal dominant inherited, disease of the brain. It is caused by a mutation in a protein called prion protein (PrP): asparagine-178 is replaced by aspartic acid.
Fatal Familial Insomnia (FFI) is a rare sleep disorder. It's genetic, and has been diagnosed in less than 40 families worldwide. Perhaps the most famous case is that of the Chicago music teacher, Michael Corke, who featured in the BBC documentary The Man Who Never Slept. FFI is a truly dark disease.