The ASNA1 gene is located at 19p13.13 and encodes an ATPase that is required for post-translational delivery of tail-anchored (TA) proteins to the endoplasmic reticulum. TA proteins are characterized by a single hydrophobic transmembrane domain near the C-terminus which serves as both a targeting signal and a membrane anchor. TA proteins constitute approximately 5% of integral membrane proteins and are involved in a variety of cellular processes, such as protein translocation, vesicle trafficking, and apoptosis.
The disease-causing ASNA1 mutations described to date either result in decreased protein expression or protein misfolding as well as less effective TA protein insertion.