rs1049793
badMag 3.5This is a protein-altering variant in the AOC1 gene.
Key Literature Trait Associations
Histamine Intolerance
AOC1 encodes diamine oxidase (DAO), the primary enzyme breaking down histamine from food in the gut. The rs1049793 variant (His645Asp) reduces DAO activity: heterozygous carriers show ~34% lower serum DAO, homozygous carriers ~49% lower. People with reduced DAO may struggle to clear histamine after eating histamine-rich foods (aged cheeses, cured meats, red wine), potentially experiencing headaches, flushing, nasal congestion, or digestive symptoms.
Blood protein measurement
A large proteomic GWAS of 5,368 Icelandic individuals identified rs1049793 as a cis-pQTL for serum protein levels at the AOC1 locus, with the G allele associated with decreased blood protein levels (beta = −0.177 SD, SE = 0.021, p = 1×10⁻¹⁷). This finding is consistent with the hypothesis that the p.His664Asp substitution reduces DAO protein stability or secretion. The association reached genome-wide significance in a single-ancestry cohort; replication in diverse populations is needed.
Fibromyalgia
In two Spanish pilot studies of women with fibromyalgia, the rs1049793 minor allele (G) was detected in approximately 48% of participants and showed a cumulative dose-effect with three other AOC1 variants on Fibromyalgia Impact Questionnaire (FIQ) scores. The proposed mechanism is that reduced DAO activity leads to elevated histamine levels, which may amplify pain signalling. However, these studies are small (n ≈ 98–100), lack independent replication, and do not isolate rs1049793's individual contribution from the other three co-genotyped AOC1 variants.
Insomnia
A 2024 study of 167 adults with insomnia-related symptoms found that 82.6% had genetic DAO deficiency based on the four-AOC1-variant panel. Among the variants, rs1049793 (c.1990C>G) was specifically associated with higher prevalence of difficulty staying asleep and early morning awakening compared to other genotype groups. The proposed mechanism is histamine's known role as a wakefulness-promoting neurotransmitter — impaired histamine degradation may disrupt sleep architecture. Evidence is from a single small observational study without a healthy-control comparison arm for this specific variant.
Attention deficit hyperactivity disorder
A 2024 pilot study of 303 children and adolescents with ADHD found that 78.8% carried at least one dysfunctional allele across four AOC1 variants. AOC1 variant burden showed a notable association with working memory performance as measured by IQ testing, and with several medical comorbidities. The study does not report rs1049793-specific statistics, and no causal mechanism linking DAO deficiency to ADHD neuropsychology has been established. Evidence is preliminary and requires replication in larger, controlled designs.
Lower urinary tract symptoms
A 2023 prevalence study in 100 patients with at least moderate lower urinary tract symptoms (LUTS) found that 85.9% met criteria for histamine intolerance, and that AOC1 minor alleles including rs1049793 were associated with greater symptom intensity. The authors propose that histamine, when inadequately metabolised due to DAO deficiency, may trigger bladder inflammation and irritation via mast cell activation. This is a small single-arm study, and rs1049793-specific effect sizes were not separately reported.
▶GWAS Catalog Trait Associations (1)
Genome-wide significant associations (p < 5×10⁻⁸) from the NHGRI-EBI GWAS Catalog.
GWAS Catalog Trait Associations (1)
Genome-wide significant associations (p < 5×10⁻⁸) from the NHGRI-EBI GWAS Catalog.
▶Research that mentions this SNP (1)
▶Variability in Ethanol Biodisposition in Whites Is Modulated by Polymorphisms in the Adh1b and Adh1c GenesReviewCarmen Martínez et al.(2010)· Hepatology
A comprehensive review of nutrigenetics and nutrigenomics examining how genetic variants influence individual responses to nutrients and dietary interventions. The paper discusses associations between numerous SNPs (rs9939609 in FTO, rs2287019 in GIPR, rs7903146 in TCF7L2, rs5219 in KCNJ11, and many others) and metabolic traits including obesity, type 2 diabetes, and other chronic diseases, along with epigenetic mechanisms by which phytochemicals (curcumin, resveratrol, lycopene) modulate gene expression. The review synthesizes current evidence for precision nutrition approaches tailored to individual genetic profiles.
Gene information from NCBI Gene. Variant classifications from ClinVar.
Community Wiki
No community notes yet for this variant. Sign in to start one.
Comments
Sign in to join the discussion.
Loading comments…