Two novel SNPs in ATXN3 3' UTR may decrease age at onset of SCA3/MJD in Chinese patients

Area of Science:

• Genetics
• Neuroscience
• Molecular Biology

Background:

• Spinocerebellar ataxia type 3 (SCA3)/Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder characterized by progressive movement problems.
• The disease is caused by CAG repeat expansions in the ATXN3 gene, with repeat length correlating with age at onset (AO) and disease severity, though not fully explaining AO variance.

Purpose of the Study:

• To investigate the association of two single nucleotide polymorphisms (SNPs), rs709930 and rs910369, in the ATXN3 3' UTR with SCA3/MJD risk and AO.
• To identify potential genetic modifiers of AO in SCA3/MJD.

Main Methods:

• Genotyping of two SNPs (rs709930 and rs910369) in the ATXN3 gene.
• Case-control study involving 170 SCA3/MJD patients and 200 healthy controls from mainland China.
• Statistical analysis to assess the association of SNP genotypes with disease risk and AO.

Main Results:

• Significant differences in rs709930 genotype frequencies were observed between SCA3/MJD patients and controls (p = 0.001).
• Patients with the rs709930 A allele and rs910369 T allele exhibited an earlier AO, with a reduction of approximately 2–4 years.
• These findings suggest a potential role for these SNPs in modifying AO in SCA3/MJD.

Conclusions:

• The identified SNPs, rs709930 and rs910369, in the ATXN3 3' UTR may act as genetic modifiers for age at onset in Spinocerebellar ataxia type 3.
• Further research is warranted to elucidate the precise mechanisms by which these SNPs influence SCA3/MJD pathogenesis.