part of part of has part has part characteristic of has modifier Abnormal circulating protein concentration Decreased circulating progranulin concentration Progranulin, a secreted glycoprotein, maintains cerebrocortical viability. It has been identified as an important factor controlling neural function while also suppressing neuroinflammation and playing roles in neuronal lysosome function. Loss of one allele of GRN, the gene encoding progranulin, leads to the development of frontotemporal dementia, and loss of both alleles leads to the development of neuronal ceroid lipofuscinosis. The concentration of progranulin in the blood circulation is below the lower limit of normal. abnormal decreased amount progranulin (human) blood