SNAP 29 is a 258 amino acid protein that localizes to the membrane and the cytoplasm, as well as to the cell junction, and contains one t-SNARE coiled-coil homology domain. Expressed in liver, heart, brain, kidney, placenta, lung, spleen, pancreas and skeletal muscle, SNAP 29 binds tightly to Syntaxins and, via this binding, is involved in membrane trafficking events. Defects in the gene encoding SNAP 29 are the cause of CEDNIK syndrome, a neurocutaneous syndrome that is associated with cerebral dysgenesis, neuropathy, ichthyosis and palmoplantar keratoderma. The gene encoding SNAP 29 maps to human chromosome 22, which houses over 500 genes and is the second smallest human chromosome. Mutations in several of the genes that map to chromosome 22 are involved in the development of Phelan-McDermid syndrome, Neurofibromatosis type 2, autism and schizophrenia.