SIRT6 rs350845 — The Longevity Guardian Variant That Shapes Your Genomic Defense System
Your cells wage a continuous war against entropy. Every day, ultraviolet radiation, reactive oxygen species,
replication errors, and jumping genetic elements called retrotransposons threaten the integrity of your DNA.
SIRT6 — a NAD+-dependent enzyme — sits at the center of this defense, coordinating DNA double-strand break
repair, telomere maintenance, retrotransposon silencing, and metabolic regulation. How well your cells wage
this war is partly determined by how much SIRT6 your genome produces, and rs350845 is one of the key
regulatory switches.
The Mechanism
rs350845 lies within an intron of the SIRT6 gene on chromosome 19p13.3. Although it does not change the
SIRT6 protein sequence, it functions as a cis-acting expression quantitative trait locus (eQTL) | a
genetic variant that influences how much of a nearby gene is transcribed into mRNA
— specifically, the A allele increases SIRT6 transcription across at least 18 tissue types. Carriers of
one or two A alleles produce measurably more SIRT6 protein than GG individuals.
SIRT6 requires NAD+ | nicotinamide adenine dinucleotide, a coenzyme that declines with age and is the
substrate that powers all sirtuin activity as a cofactor to
perform two distinct enzymatic reactions: histone deacetylation (removing acetyl marks from histones H3K9
and H3K56 to compact chromatin at DNA break sites and telomeres) and mono-ADP ribosylation (chemically
tagging proteins like PARP1 and KAP1 to recruit repair machinery and silence retrotransposons).
When SIRT6 levels are high — as in A-allele carriers — these two functions operate more robustly:
- DNA double-strand break repair: SIRT6 stabilizes DNA-PK and recruits repair factors within seconds of a break occurring. Higher expression means more rapid response to genotoxic insults.
- LINE1 retrotransposon silencing: SIRT6 mono-ADP ribosylates KAP1, which in turn recruits HP1α to package LINE1 elements into condensed, transcriptionally silent heterochromatin (Van Meter et al., Nature Communications 2014). During aging, SIRT6 becomes depleted from these loci and LINE1s reactivate — driving inflammation and genomic instability. GG individuals, producing less baseline SIRT6, may reach this depletion threshold earlier.
- Telomere maintenance: SIRT6 deacetylates H3K9 at telomeric chromatin, stabilizing the protective cap structure. Insufficient SIRT6 causes telomere uncapping and chromosomal end-joining.
The Evidence
The primary human evidence for rs350845 comes from a 2022 study of 450 Ashkenazi Jewish (AJ) centenarians
and 550 AJ controls
(Simon et al., EMBO Journal 2022). The A allele was present
in 17.2% of centenarian chromosomes compared to 12.6% in controls (p = 0.009), a nominally significant
enrichment replicated against gnomAD reference frequencies (p = 0.007). The same study noted that rs350845
is in near-perfect linkage disequilibrium (r² > 0.98) with rs350843 and rs350846, which also upregulate
SIRT6 — all three eQTLs are effectively measuring the same longevity signal.
The causal link between higher SIRT6 and longer life is robustly supported by animal models. SIRT6
transgenic male mice showed 14.5% mean lifespan extension with reduced IGF1 signaling
(Kanfi et al., Nature 2012). A later study achieved
lifespan extension in both sexes by restoring energy homeostasis in aged animals, with SIRT6 overexpression
enhancing hepatic NAD+ synthesis and maintaining glucose output through improved gluconeogenic substrate
utilization
(Roichman et al., Nature Communications 2021).
Across mammalian species, SIRT6 DNA double-strand break repair efficiency correlates strongly with maximum
lifespan — longer-lived species simply have more active SIRT6.
A separate rs350845 association was reported for Parkinson's disease risk in a Hungarian cohort
(Torok et al., Scientific Reports 2021), but the finding was
not significant after false discovery rate correction and should be considered exploratory.
The evidence level for rs350845 is moderate: the longevity association is nominally significant in one
well-designed cohort and is mechanistically coherent, but replication in non-Ashkenazi populations and
larger genome-wide studies is needed to establish it at the strong level.
Practical Implications
The core implication of this SNP is about NAD+ sufficiency and DNA-damage avoidance. SIRT6 is
NAD+-dependent, and NAD+ declines ~50% by age 60 in humans. GG individuals, who already produce less
baseline SIRT6, are more exposed to the functional consequences of this decline. Supporting NAD+ levels
with precursors and protecting against unnecessary DNA damage (ionizing radiation, genotoxic chemicals,
tobacco carcinogens) become especially relevant for GG carriers.
For AG and AA carriers, the A allele provides partial to full upregulation of SIRT6 expression — but
this benefit still depends on adequate NAD+ availability to keep the enzyme active. All genotypes benefit
from NAD+ support, but the priority is highest for GG.
Interactions
rs350845 is in high LD with rs350843 and rs350846, which tag the same SIRT6-upregulating haplotype.
These are not independent signals.
rs107251 is a separate SIRT6 intronic variant (not in LD with rs350845) associated with >5-year mean
survival advantage for CC and CT carriers vs TT in an Iowa aging cohort
(TenNapel et al., PLOS ONE 2014). Individuals who carry the
protective allele at both rs350845 (A) and rs107251 (C) likely enjoy additive SIRT6-related genomic
stability benefits, though formal compound analysis has not been published.
rs12696304 (TERC) influences telomere length through the telomerase RNA component. Since SIRT6 also
regulates telomere chromatin stability, GG carriers at rs350845 who also carry G alleles at rs12696304
face a double burden of reduced telomere protection: less SIRT6-mediated heterochromatin at telomere ends
AND shorter baseline telomere length from reduced telomerase activity. Both variants are in the longevity
category and their interaction is mechanistically plausible, though specific compound data are lacking.
For the supervisor: a compound action covering rs350845 GG + rs12696304 GG would target individuals with
dual telomere vulnerability — reduced SIRT6-mediated telomere chromatin stability AND reduced telomerase
RNA activity. Combined recommendation: prioritize NAD+ precursor supplementation to maximize SIRT6
activity and emphasize high-MUFA dietary patterns (CORDIOPREV evidence) plus monitoring telomere-associated
biomarkers. Evidence level: emerging (mechanistically coherent, no published compound study).
All Genotypes
Common genotype with baseline SIRT6 genomic defense capacity
You have two copies of the G allele at rs350845 — the most common genotype, found in approximately 78% of people globally. This is the reference genotype: your SIRT6 gene is regulated at its typical baseline level, without the additional transcriptional boost associated with the A allele. This does not indicate disease. It simply means you do not carry the longevity-associated eQTL variant identified in Ashkenazi centenarians. Your SIRT6 genomic stability functions are intact but not enhanced beyond the population baseline.
One protective A allele provides partial upregulation of SIRT6 across multiple tissues
You carry one copy of the longevity-associated A allele at rs350845. This eQTL variant upregulates SIRT6 expression across at least 18 tissue types, giving you intermediate levels of SIRT6 above the GG baseline. In the Ashkenazi centenarian study, approximately 21% of centenarian chromosomes would be expected to be AG (heterozygous), and the A allele showed a nominally significant enrichment among people who lived past 100 (17.2% of centenarian alleles vs 12.6% in controls, p=0.009). The A allele frequency is approximately 12% in European populations. Higher SIRT6 expression supports more efficient DNA double-strand break repair, stronger silencing of LINE1 retrotransposons, and more robust telomere chromatin maintenance — all mechanisms implicated in slowing the aging process.
Two copies of the protective A allele drive highest SIRT6 expression and maximal genomic stability benefit
You carry two copies of the A allele at rs350845, the genotype associated with maximum SIRT6 upregulation across all 18 tissue types studied. This is the rarest genotype — approximately 1.4% of the global population — and corresponds to homozygosity for the longevity-associated eQTL allele that was enriched in Ashkenazi centenarians (A allele frequency: 17.2% in centenarians vs 12.6% in controls, p=0.009). With two A alleles driving SIRT6 transcription, your genome produces the highest baseline levels of SIRT6 protein, supporting the most robust capacity for DNA double-strand break repair, LINE1 retrotransposon silencing, and telomere chromatin stabilization among the three genotypes at this locus.