Abstract
Meng-Hui Dai1,*, Hui Zheng2,*, Ling-Dan Zeng1 and Yan Zhang1
1Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
2Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
*These authors contributed equally to this work
Correspondence to:
Ling-Dan Zeng, email: 34187746@qq.com
Yan Zhang, email: 799896551@qq.com
Keywords: Alzheimer’s disease; early-onset AD; APP; PSEN1; PSEN2
Received: June 06, 2017 Accepted: October 14, 2017 Epub: December 15, 2017 Published: March 13, 2018
ABSTRACT
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that accounts for the most cases of dementia, which is characterized by the deposition of dense plaques of amyloid beta (Aβ) plaques and neurofibrillary tangles consisting of hyperphosphorylated tau. The two main types of AD can be classified as early-onset AD (EOAD, onset < 65 years) and late-onset AD (LOAD, onset ≥ 65 years). Evidence from family and twin studies indicate that genetic factors are estimated to play a role in at least 80% of AD cases. The first milestone with linkage analysis revealed the mutations in APP, PSEN1, and PSEN2 genes that cause EOAD. But pathogenic mutations in these three genes can only explain a small fraction of EOAD families. The additional disease-causing genes have not yet been identified. This review provides an overview of the genetic basis of EOAD and the relationship between the functions of these risk genes and the neuropathologic features of AD. A better understanding of genetic mechanisms underlying EOAD pathogenesis and the potentially molecular mechanisms of neurodegeneration will lead to the development of effective diagnosis and treatment strategies for this devastating disease.