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Updated: Jun 22, 2026

Generalized Psychophysiological Interaction (PPI) Analysis of Memory Related Connectivity in Individuals at Genetic Risk for Alzheimer's Disease
Published on: November 14, 2017
A case of dementia with PRNP D178Ncis-129M and no insomnia
Rita J Guerreiro1, Tina Vaskov, Cynthia Crews
1Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA. portalegrer@nia.nih.gov
Objective:
To describe a dementia case clinically diagnosed as Alzheimer disease with a PRNP genotype usually associated with familial fatal insomnia.
Methods:
Polymerase chain reaction amplification and subsequent direct sequencing of PGRN, MAPT, PSEN1, PSEN2, APP, and PRNP genes.
Results:
A point mutation (D178N) was found in the PRNP gene.
Conclusions:
The mutation D178N in the PRNP gene associated with the M129 genotype is usually associated with familial fatal insomnia. However, a few cases have been reported with different clinical phenotypes. Here, we describe one of these cases and stress the importance of genetic screening of PRNP in early onset dementia cases.
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