Expanded Phenotypic Spectrum of Cerebral Dysgenesis, Neuropathy, Ichthyosis, and Keratoderma (CEDNIK) Syndrome: A Rare Case Featuring Supraventricular Tachycardia and Tethered Spinal Cord.

Cerebral dysgenesis, neuropathy, ichthyosis, and keratoderma (CEDNIK) syndrome is a rare, autosomal recessive neurocutaneous disorder. It represents a progressive neurodegenerative condition caused by mutations in the synaptosome-associated protein 29 (SNAP29) gene, which encodes a member of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family. This protein plays a critical role in intracellular membrane fusion and protein trafficking. Mutations in SNAP29 disrupt normal cellular processes, resulting in a broad spectrum of clinical manifestations, including facial dysmorphisms, microcephaly, severe developmental delay, hypotonia, ichthyosis, and peripheral neuropathy. In this report, we describe a rare case of CEDNIK syndrome featuring novel clinical findings, supraventricular tachycardia (SVT) and a tethered spinal cord, both of which have not been previously documented in association with this syndrome. These observations contribute to the expanding phenotypic spectrum of CEDNIK syndrome.