NDC1 is a 674 amino acid multi-pass membrane protein, central core structure of the nuclear pore complex (NPC) and member of the NDC1 family that is crucial for selective nuclear protein import. Existing as four alternatively spliced isoforms that are encoded by a gene located on human chromosome 1, NDC1 interacts with Nup35 and anchors Aladin to the nuclear envelope of the NPC, a region of macromolecular transport between the nucleus and cytoplasm. In the absence of NDC1, Aladin becomes mislocalized and may lead to the development of an autosomal recessive disorder termed achalasia-addisonianism-alacrima (triple A) syndrome. Triple A syndrome is characterized by achalasia, alacrima and adrenocortico-tropin-resistant adrenal insufficiency. Robust expression in neural systems associated with cognitive, motor and sensory functions is consistent with the myriad of symptoms experienced by patients with triple A syndrome.