It is secreted from pyramidal neurons and is considered a biomarker for AD.[29] Its levels are shown to decrease in Alzheimer disease, and it is a strong predictor of progression from mild cognitive impairment to Alzheimer disease.[30,31,32] In the present study, although serum levels of NPTX2 were lower in the POAG group compared to healthy controls and the OHT group, the difference was not significant. This evidence concerns the gene NPTX2 and early-onset autosomal dominant Alzheimer disease.