SNAP29 and neuropathy: Cerebral dysgenesis, neuropathy, ichthyosis, and keratoderma (CEDNIK) syndrome is a rare, autosomal recessive neurodegenerative disorder caused by mutations in the synaptosome-associated protein 29 (SNAP29) gene, located on chromosome 22 and encoding a member of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein family.