Session Information
Date: Tuesday, June 21, 2016
Session Title: Parkinson's disease: Genetics
Session Time: 12:30pm-2:00pm
Location: Exhibit Hall located in Hall B, Level 2
Objective: To report the case of a patient carrying the G2019S mutation of the LRRK2 gene presenting with progressive logopenic aphasia and not manifesting PD motor symptoms.
Background: LRRK2 mutations have been associated histopathologically with Lewy body disease, neurofibrillary tangles, and nonspecific neuronal loss. Despite this pleomorphic pathology, LRRK2 mutations are believed to manifest clinically in a manner that is indistinguishable from idiopathic Parkinson’s disease (PD). The G2019S mutation of the LRRK2 gene represents the commonest known cause of PD, however unusual phenotypes associated with this mutation have been reported.
Methods: This 64 year-old woman belonged to a pedigree afected by LRRK2 G201S mutation, causing PD in her mother and maternal aunt. She had started noticing speech problems since two years before. Examination showed non-fluent logopenic aphasia, together with some memory loss. Motor examination was within normal limits without any sign of parkinsonism.
Results: Brain MRI revealed no abnormalities. DaTSCAN showed bilateral reduction of DAT binding in both putamen. 18F-FDG PET showed bilateral temporo-parietal hypometabolism. C11-PIB PET showed an intense retention of the compound at the cerebral cortex. On genetic testing she was a LRRK2 G2019S heterozygote. A diagnosis of Alzheimer’s disease (AD) with a logopenic aphasia phenotype was done. The patient was also likely to be in the premotor stage of LRRK2 G2019S-associated PD.
Conclusions: Coexisting AD is the most likely diagnosis in this “asymptomatic” G2019S carrier. Whether or not there is a crosstalk between the two different conditions in this case cannot be answered, however interactions between different proteinopathies are known to occur. This case also illustrates how PET and SPECT studies can be helpful in deciphering the nature of complex neurodegenerative conditions.
To cite this abstract in AMA style:
S. López, A. Pozueta, M. Sierra, R. Quirce, P. Sánchez-Juan, I. González-Aramburu, C. Sánchez-Quintana, J.M. Carril, J. Infante. LRRK2 G2019S mutation carrier with an unusual phenotype: Progressive logopenic aphasia [abstract]. Mov Disord. 2016; 31 (suppl 2). https://www.mdsabstracts.org/abstract/lrrk2-g2019s-mutation-carrier-with-an-unusual-phenotype-progressive-logopenic-aphasia/. Accessed June 14, 2025.« Back to 2016 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/lrrk2-g2019s-mutation-carrier-with-an-unusual-phenotype-progressive-logopenic-aphasia/