We measured hypothalamic volume in 18 patients with bvFTD (including 9 MAPT and 6 C9orf72 mutation carriers) and 18 cognitively normal controls using a novel optimized multimodal segmentation protocol, combining 3D T1 and T2-weighted 3T MRIs (intrarater intraclass correlation coefficients ≥0.93).
Low PGRN levels were detected in 7 individuals (5 behavioral variant frontotemporal dementia, 1 CBS, and 1 still clinically unaffected) that constituted the group of the null PGRN mutation carriers previously identified in our molecular diagnostic laboratory.
Eighty-one patients with sporadic bvFTD were genotyped for tauopathy-associated SNPs at rs8070723 (microtubule-associated protein tau [MAPT]) and rs1768208 (myelin-associated oligodendrocyte basic protein [MOBP]).
The clinical presentation of the GRN A9D missense mutation is not restricted to behavioral variant frontotemporal dementia and may include aphasia, extrapyramidal features, and, notably, amyotrophic lateral sclerosis.
Progranulin (GRN) mutations are typically associated with the behavioral variant of frontotemporal dementia and the non-fluent variant of primary progressive aphasia phenotypes.
Herein, we describe the clinical, neuropathological, and genetic findings in a case of autosomal dominant behavioral variant of frontotemporal dementia (bvFTD) with asymmetrical parkinsonism and prominent visuospatial deficits that carries a novel GRN mutation.
Microtubule-associated protein tau gene mutations have been the first ones identified, and are generally associated with early onset (40-50 years) and with the bvFTD phenotype.
The asymptomatic MAPT subjects and subjects with bvFTD showed altered functional connectivity in the DMN, with reduced in-phase connectivity in lateral temporal lobes and medial prefrontal cortex, compared to controls.
The same mutation was recently described in a case of progressive non-fluent aphasia, but the prominent presenting feature in tau gene mutation cases is the behavioral variant of frontotemporal dementia, with typical symmetrical frontotemporal atrophy.
PGRN mutations at 17q21 may occur in apparently sporadic frontotemporal lobar dementia with ubiquitinated inclusions cases and in cases presenting with either primary progressive aphasia or the behavioral variant of frontotemporal dementia.
Herein, we report a Chinese Han consanguineous family carrying a novel TREM2 mutation, presenting with early-onset dementia similar to behavioral variant frontotemporal dementia with mild radiological bone involvement.