Parkinson-ALS with a novel MAPT variant.

Area of Science:

• Neurogenetics
• Molecular Neurology
• Clinical Neuroscience

Background:

• Mutations in the microtubule-associated protein tau (MAPT) gene are linked to frontotemporal dementia (FTD), parkinsonism (e.g., progressive supranuclear palsy, corticobasal degeneration), and amyotrophic lateral sclerosis (ALS).
• MAPT gene mutations lead to tau protein dysfunction and neurofibrillary tangle accumulation.
• Co-occurrence of tau and alpha-synuclein aggregates is frequently observed in parkinsonism and Parkinson disease (PD), suggesting protein interactions in neurodegeneration.

Observation:

• The case study focuses on a 54-year-old Italian woman initially diagnosed with idiopathic Parkinson disease (PD).
• The patient later developed amyotrophic lateral sclerosis (ALS), presenting a rare PD-ALS clinical complex.
• Genetic analysis revealed a novel MAPT variant, Pro494Leu, in this patient.

Findings:

• The novel MAPT variant (Pro494Leu) involves an amino acid substitution.
• This variant is predicted to be damaging to MAPT gene function.
• The identified variant provides a specific genetic link in a patient with both PD and ALS.

Implications:

• This case supports the hypothesis that tau protein dysfunction is a common underlying mechanism in various neurodegenerative disorders.
• It highlights the potential role of MAPT variants in the pathogenesis of overlapping conditions like PD and ALS.
• Further research into tau pathology may offer insights into shared pathways across different neurodegenerative diseases.