Molecular characterization of genes modifying the age at onset in Huntington's disease in Uruguayan patients

Analysis of association of ADORA2A and ADORA3 polymorphisms genotypes/haplotypes with efficacy and toxicity of methotrexate in patients with Rheumatoid arthritis

Adenosine receptors ADORA₂A and ADORA₃ are part of the adenosine-mediated antiinflammatory pathway and are overexpressed in patients with Rheumatoid arthritis (RA). Methotrexate (MTX) antiinflammatory effects are partially mediated via increased release of adenosine into extracellular space. Polymorphisms in ADORA₂A and ADORA₃ genes may have an impact on the efficacy and toxicity of MTX in RA patients. The study included 127 RA patients. Treatment efficacy was estimated using the changes in Disease activity score (DAS28) after 6 months of MTX monotherapy, according to EULAR response criteria. Patients with good and moderate response were classified as "responders", and with a poor response as "nonresponders". Adverse effects were collected during the follow-up period. Genotyping for polymorphisms within ADORA₂A gene (rs2298383, rs2236624, rs5751876, rs17004921) and ADORA₃ gene (rs2298191, rs1544223, rs3393) was performed using the KASPar assays. Among patients 112 (88.19%) were responders (18.8% good, 81.2% moderate). We observed no association between analyzed genotypes or alleles and MTX response by EULAR criteria but carriers of ADORA₂A rs17004921 T allele (CT + TT) had a higher DAS28 decrease after 6 months of treatment than patients with CC genotype (p = 0.013). Adverse effects were reported in 31 patients (24.41%). Bone erosions were present in 82 (64.6%) patients. Haplotype block was observed among all 3 analyzed polymorphisms within ADORA₃ gene and TAA haplotype was associated with bone erosions (29% vs 15.6%, p = 0.023) and hepatotoxicity (51.3% vs 21.6%, p = 0.013). According to our study, ADORA₃ TAA haplotype may be associated with bone erosions and hepatotoxicity in RA patients treated with MTX.

Genetics Modulate Gray Matter Variation Beyond Disease Burden in Prodromal Huntington's Disease

Huntington’s disease (HD) is a neurodegenerative disorder caused by an expansion mutation of the cytosine–adenine–guanine (CAG) trinucleotide in the HTT gene. Decline in cognitive and motor functioning during the prodromal phase has been reported, and understanding genetic influences on prodromal disease progression beyond CAG will benefit intervention therapies. From a prodromal HD cohort (N = 715), we extracted gray matter (GM) components through independent component analysis and tested them for associations with cognitive and motor functioning that cannot be accounted for by CAG-induced disease burden (cumulative effects of CAG expansion and age). Furthermore, we examined genetic associations (at the genomic, HD pathway, and candidate region levels) with the GM components that were related to functional decline. After accounting for disease burden, GM in a component containing cuneus, lingual, and middle occipital regions was positively associated with attention and working memory performance, and the effect size was about a tenth of that of disease burden. Prodromal participants with at least one dystonia sign also had significantly lower GM volume in a bilateral inferior parietal component than participants without dystonia, after controlling for the disease burden. Two single-nucleotide polymorphisms (SNPs: rs71358386 in NCOR1 and rs71358386 in ADORA2B) in the HD pathway were significantly associated with GM volume in the cuneus component, with minor alleles being linked to reduced GM volume. Additionally, homozygous minor allele carriers of SNPs in a candidate region of ch15q13.3 had significantly higher GM volume in the inferior parietal component, and one minor allele copy was associated with a total motor score decrease of 0.14 U. Our findings depict an early genetical GM reduction in prodromal HD that occurs irrespective of disease burden and affects regions important for cognitive and motor functioning.