[Neuropathologic Subtypes of Frontotemporal Lobar Degeneration]

Area of Science:

• Neuroscience
• Genetics
• Pathology

Background:

• Frontotemporal lobar degeneration (FTLD) is a heterogeneous neurodegenerative disease.
• Recent decades revealed causative genes and key proteins implicated in FTLD.
• Current classification relies on protein deposition: FTLD-tau, FTLD-TDP, and FTLD-FUS.

Purpose of the Study:

• To review the histopathological features of major FTLD subtypes.
• To summarize clinical presentations and genetic characteristics of FTLD patients.
• To correlate pathological subtypes with clinical syndromes and genetic backgrounds.

Main Methods:

• Review of histopathological classifications of FTLD.
• Analysis of clinical heterogeneity within FTLD subgroups.
• Summary of genetic findings associated with specific FTLD phenotypes.

Main Results:

• FTLD is classified into FTLD-tau, FTLD-TDP, and FTLD-FUS based on protein aggregates.
• Clinical presentations vary widely, including frontotemporal dementia and motor neuron diseases.
• Specific gene mutations (e.g., MAPT, GRN, C9orf72) are linked to distinct FTLD subtypes.

Conclusions:

• FTLD subtypes, defined by proteinopathy, represent distinct clinical syndromes.
• Genetic factors play a crucial role in FTLD pathogenesis and presentation.
• Understanding FTLD subtypes is essential for accurate diagnosis and future therapeutic strategies.