To explore the clinical and neuroimaging features of a frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) pedigree caused by mutation of microtubule-associated protein tau (MAPT) gene.

The proband and one patient from a FTDP-17 pedigree were assessed through standardized clinical evaluation, neuropsychology assessment, video-electroencephalogrom, MRI, genetic sequencing, as well as ¹⁸F fludeoxyglucose (FDG) SPECT for brain metabolism and ¹¹C 2β-carbomethoxy-3β-(4-fluoro)tropane (CFT) PET for dopamine transporter (DAT) distribution, respectively.

A FTDP pedigree with 15 patients (6 still alive) was recruited to this study. The proband and one affected patient were genotyped and confirmed as MAPT c. 1788T>G mutation. Parkinsonism was the first symptom for both two patients. Personality, speech changes and dementia accompanied with brain atrophy were developed at the later stage in one patient. The ¹⁸F FDG SPECT studies illustrated asymmetric hypometabolism of the temporal, frontal lobes and basal ganglia in two patients. Regarding to the ¹¹C CFT PET, one affected patient showed asymmetric decreased uptake of tracer in basal ganglia regions.

FTDP-17 can display a confusingly broad clinical phenotype, with the parkinsonism as the first symptom. Brain glucose metabolism and DAT distribution could be potential biomarkers in early diagnosis of FTDP-17.

Frontotemporal dementia; Parkinsonism; Microtubule-associated protein tau gene; Glucose metabolism; Dopamine transporter