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dbSNP Short Genetic Variations

Welcome to the Reference SNP (rs) Report

All alleles are reported in the Forward orientation. Click on the Variant Details tab for details on Genomic Placement, Gene, and Amino Acid changes. HGVS names are in the HGVS tab.

Reference SNP (rs) Report

This page reports data for a single dbSNP Reference SNP variation (RefSNP or rs) from the new redesigned dbSNP build.
Top of the page reports a concise summary for the rs, with more specific details included in the corresponding tabs below.
All alleles are reported in the Forward orientation. Use the Genomic View to inspect the nucleotides flanking the variant, and its neighbors.
For more information see Help documentation.


Current Build 155

Released April 9, 2021

Homo sapiens
chr21:13021266 (GRCh38.p13) Help

The anchor position for this RefSNP. Includes all nucleotides potentially affected by this change, thus it can differ from HGVS, which is right-shifted. See here for details.

C>G / C>T
Variation Type
SNV Single Nucleotide Variation
T=0.000008 (1/130362, GnomAD)
C=0.42035 (7045/16760, 8.3KJPN)
G=0.49602 (8101/16332, ALFA) (+ 3 more)
C=0.4352 (1269/2916, KOREAN)
C=0.438 (149/340, SGDP_PRJ)
G=0.269 (58/216, Qatari)
Clinical Significance
Not Reported in ClinVar
Gene : Consequence
0 citations
Genomic View
See rs on genome

Variant Details tab shows known variant placements on genomic sequences: chromosomes (NC_), RefSeqGene, pseudogenes or genomic regions (NG_), and in a separate table: on transcripts (NM_) and protein sequences (NP_). The corresponding transcript and protein locations are listed in adjacent lines, along with molecular consequences from Sequence Ontology. When no protein placement is available, only the transcript is listed. Column "Codon[Amino acid]" shows the actual base change in the format of "Reference > Alternate" allele, including the nucleotide codon change in transcripts, and the amino acid change in proteins, respectively, allowing for known ribosomal slippage sites. To view nucleotides adjacent to the variant use the Genomic View at the bottom of the page - zoom into the sequence until the nucleotides around the variant become visible.

Genomic Placements
Sequence name Change
GRCh38.p13 chr 21 NC_000021.9:g.13021266C>G
GRCh38.p13 chr 21 NC_000021.9:g.13021266C>T
GRCh37.p13 chr 21 NC_000021.8:g.14393587C>G
GRCh37.p13 chr 21 NC_000021.8:g.14393587C>T

Clinical Significance tab shows a list of clinical significance entries from ClinVar associated with the variation, per allele. Click on the RCV accession (i.e. RCV000001615.2) or Allele ID (i.e. 12274) to access full ClinVar report.

Not Reported in ClinVar

ALFA Allele Frequency
The ALFA project provide aggregate allele frequency from dbGaP. More information is available on the project page including descriptions, data access, and terms of use.

Release Version: 20201027095038
Population Group Sample Size Ref Allele Alt Allele
Total Global 16332 C=0.50398 G=0.49602
European Sub 12080 C=0.53171 G=0.46829
African Sub 2816 C=0.3881 G=0.6119
African Others Sub 108 C=0.389 G=0.611
African American Sub 2708 C=0.3881 G=0.6119
Asian Sub 108 C=0.481 G=0.519
East Asian Sub 84 C=0.48 G=0.52
Other Asian Sub 24 C=0.50 G=0.50
Latin American 1 Sub 146 C=0.473 G=0.527
Latin American 2 Sub 610 C=0.508 G=0.492
South Asian Sub 94 C=0.50 G=0.50
Other Sub 478 C=0.496 G=0.504


Frequency tab displays a table of the reference and alternate allele frequencies reported by various studies and populations. Table lines, where Population="Global" refer to the entire study population, whereas lines, where Group="Sub", refer to a study-specific population subgroupings (i.e. AFR, CAU, etc.), if available. Frequency for the alternate allele (Alt Allele) is a ratio of samples observed-to-total, where the numerator (observed samples) is the number of chromosomes in the study with the minor allele present (found in "Sample size", where Group="Sub"), and the denominator (total samples) is the total number of all chromosomes in the study for the variant (found in "Sample size", where Group="Study-wide" and Population="Global").

Study Population Group Sample Size Ref Allele Alt Allele
gnomAD - Genomes Global Study-wide 130362 C=0.999992 T=0.000008
gnomAD - Genomes European Sub 70694 C=1.00000 T=0.00000
gnomAD - Genomes African Sub 39032 C=0.99997 T=0.00003
gnomAD - Genomes American Sub 12572 C=1.00000 T=0.00000
gnomAD - Genomes Ashkenazi Jewish Sub 3166 C=1.0000 T=0.0000
gnomAD - Genomes East Asian Sub 2920 C=1.0000 T=0.0000
gnomAD - Genomes Other Sub 1978 C=1.0000 T=0.0000
8.3KJPN JAPANESE Study-wide 16760 C=0.42035 G=0.57965
KOREAN population from KRGDB KOREAN Study-wide 2916 C=0.4352 G=0.5648
SGDP_PRJ Global Study-wide 340 C=0.438 G=0.562
Qatari Global Study-wide 216 C=0.731 G=0.269

Aliases tab displays HGVS names representing the variant placements and allele changes on genomic, transcript and protein sequences, per allele. HGVS name is an expression for reporting sequence accession and version, sequence type, position, and allele change. The column "Note" can have two values: "diff" means that there is a difference between the reference allele (variation interval) at the placement reported in HGVS name and the reference alleles reported in other HGVS names, and "rev" means that the sequence of this variation interval at the placement reported in HGVS name is in reverse orientation to the sequence(s) of this variation in other HGVS names not labeled as "rev".

Placement C= G T
GRCh38.p13 chr 21 NC_000021.9:g.13021266= NC_000021.9:g.13021266C>G NC_000021.9:g.13021266C>T
GRCh37.p13 chr 21 NC_000021.8:g.14393587= NC_000021.8:g.14393587C>G NC_000021.8:g.14393587C>T

Submissions tab displays variations originally submitted to dbSNP, now supporting this RefSNP cluster (rs). We display Submitter handle, Submission identifier, Date and Build number, when the submission appeared for the first time. Direct submissions to dbSNP have Submission ID in the form of an ss-prefixed number (ss#). Other supporting variations are listed in the table without ss#.

20 SubSNP, 6 Frequency submissions
No Submitter Submission ID Date (Build)
1 PERLEGEN ss3995635 Sep 28, 2001 (100)
2 HGSV ss81363871 Dec 15, 2007 (147)
3 ENSEMBL ss135656628 Dec 01, 2009 (131)
4 1000GENOMES ss237904854 Jul 15, 2010 (147)
5 GMI ss283460422 May 04, 2012 (147)
6 SSMP ss662271431 Apr 25, 2013 (147)
7 DDI ss1429120838 Apr 01, 2015 (147)
8 WEILL_CORNELL_DGM ss1938466623 Feb 12, 2016 (147)
9 GRF ss2704318455 Nov 08, 2017 (151)
10 GNOMAD ss2969712980 Nov 08, 2017 (151)
11 SWEGEN ss3018580261 Nov 08, 2017 (151)
12 TOPMED ss3366037648 Nov 08, 2017 (151)
13 URBANLAB ss3651071885 Oct 12, 2018 (152)
14 EVA ss3758882033 Jul 13, 2019 (153)
15 PACBIO ss3788708615 Jul 13, 2019 (153)
16 PACBIO ss3793589915 Jul 13, 2019 (153)
17 PACBIO ss3798476148 Jul 13, 2019 (153)
18 SGDP_PRJ ss3889593919 Apr 27, 2020 (154)
19 KRGDB ss3939993790 Apr 27, 2020 (154)
20 TOMMO_GENOMICS ss5230696299 Apr 26, 2021 (155)
21 gnomAD - Genomes NC_000021.9 - 13021266 Apr 26, 2021 (155)
22 KOREAN population from KRGDB NC_000021.8 - 14393587 Apr 27, 2020 (154)
23 Qatari NC_000021.8 - 14393587 Apr 27, 2020 (154)
24 SGDP_PRJ NC_000021.8 - 14393587 Apr 27, 2020 (154)
25 8.3KJPN NC_000021.8 - 14393587 Apr 26, 2021 (155)
26 ALFA NC_000021.9 - 13021266 Apr 26, 2021 (155)

History tab displays RefSNPs (Associated ID) from previous builds (Build) that now support the current RefSNP, and the dates, when the history was updated for each Associated ID (History Updated).

Associated ID History Updated (Build)
rs58642418 Jul 19, 2016 (147)
Added to this RefSNP Cluster:
Submission IDs Observation SPDI Canonical SPDI Source RSIDs
ss81363871, ss283460422 NC_000021.7:13315457:C:G NC_000021.9:13021265:C:G (self)
47171184, 20508545, 41610899, 88665606, ss237904854, ss662271431, ss1429120838, ss1938466623, ss2704318455, ss2969712980, ss3018580261, ss3758882033, ss3788708615, ss3793589915, ss3798476148, ss3889593919, ss3939993790, ss5230696299 NC_000021.8:14393586:C:G NC_000021.9:13021265:C:G (self)
7543557409, ss3366037648, ss3651071885 NC_000021.9:13021265:C:G NC_000021.9:13021265:C:G (self)
ss3995635, ss135656628 NT_011512.11:55457:C:G NC_000021.9:13021265:C:G (self)
557943029 NC_000021.9:13021265:C:T NC_000021.9:13021265:C:T

Publications tab displays PubMed articles citing the variation as a listing of PMID, Title, Author, Year, Journal, ordered by Year, descending.

No publications for rs2821577


The Flanks tab provides retrieving flanking sequences of a SNP on all molecules that have placements.

Genome context:
Select flank length:

Genomic regions, transcripts, and products
Top Help

NCBI Graphical Sequence Viewer display of the genomic region, transcripts and protein products for the reported RefSNP (rs).
Use the zoom option to view the nucleotides around the RefSNP and find other neighboring RefSNPs.
Visit Sequence Viewer for help with navigating inside the display and modifying the selection of displayed data tracks.

Software version is: 2.0.1.post596+ae089ad