Abstract
Background: Early-onset Alzheimer's disease is defined as Parkinson's disease that begins at an age of 65 or younger. Currently, among the reports on early-onset Alzheimer's disease related genes, mutations of APP, PSEN1 and PSEN2 genes are relatively common, However, the mutation of MAPT P301L causes early-onset Alzheimer's disease, which has not been reported so far. Case report: We have found a clinical case of a 30-year-old male who suddenly developed cognitive impairment and progressed rapidly within 2 years, leaving him unable to take care of himself. The patient underwent examinations of blood and cerebrospinal fluid routine, biochemistry and immunoassay, as well as imaging examinations of MRI, FDGPET and PIBPET. PIB-PET indicated diffuse heterogeneous radionuclivity in cerebral cortex, and positive PIB imaging was considered. Sequencing results suggested that there was a heterozygous mutation in the MAPT gene of the patient, which was located in Chr17-44087755, and c.902C>T. Conclusion: We speculated that EOAD of this patient may be related to the P301L mutation on MAPT.