Serum progranulin level in a subject carrying ‘predicted’ pathogenic PGRN mutation p.R564C

ABSTRACT

Although most of the known pathogenic mutations in the progranulin gene (PGRN) are null mutations leading to a reduction in the serum PGRN protein levels, missense mutations also have been identifi ed in patients with frontotemporal lobar degeneration and in patients with Alzheimer disease. Among these, p.R564C mutation was identifi ed in a late-onset AD patient with a reduced serum PGRN level. However, recently, we found the p.R564C mutation in a healthy control subject raising doubts whether this is a pathogenic mutation. In this report, we measured the serum PGRN levels in 20 subjects without the p.R564C mutation and in one subject with the p.R564C mutation, to determine whether the p.R564C mutation is associated with reduced serum PGRN levels. We found that the serum PGRN level in the subject with the p.R564C mutation was not reduced compared to the subjects without the p.R564C mutation. Our result reiterates that p.R564C may not be a pathogenic mutation.