MAPT haplotype diversity in multiple system atrophy

Area of Science:

• Neurogenetics
• Neurodegenerative Diseases

Background:

• Multiple system atrophy (MSA) is a rare, progressive neurodegenerative disorder.
• While often sporadic, genetic factors like SNCA, COQ2, and LRRK2 are implicated in MSA.
• The MAPT gene, associated with other neurodegenerative diseases, was previously linked to a protective H2 haplotype in MSA.

Purpose of the Study:

• To investigate the full MAPT haplotype diversity in Multiple System Atrophy (MSA) patients.
• To determine the association between MAPT haplotypes and MSA risk and subtypes.

Main Methods:

• Genotyping of six MAPT tagging single nucleotide polymorphisms (SNPs).
• Analysis of 127 pathologically confirmed MSA cases, 86 clinically diagnosed MSA patients, and 1312 controls.
• Evaluation of MAPT haplotype associations with MSA and its subtypes (MSA-C and MSA-P).

Main Results:

• Four significant association signals for MAPT haplotypes were identified in pathologically confirmed MSA cases.
• Protective haplotypes H2 and H1E, and risk haplotypes H1x and H1J showed significant associations.
• The protective H2 haplotype was significantly less frequent in MSA-C (cerebellar subtype) patients compared to controls (P < 0.0001).

Conclusions:

• MAPT gene variations are associated with the risk of developing Multiple System Atrophy (MSA).
• The protective effect of the H2 haplotype appears more pronounced in MSA-C compared to MSA-P (parkinsonian subtype).
• Further large-scale genetic studies and meta-analyses are necessary to fully elucidate the role of MAPT in MSA pathogenesis.