{{Rsnum
|rsid=1801270
|Gene=CDKN1A
|Chromosome=6
|position=36684194
|Orientation=plus
|GMAF=0.247
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(A;A)
|geno2=(A;C)
|geno3=(C;C)
|Gene_s=CDKN1A
}}{{ population diversity
| geno1=(A;A)
| geno2=(A;C)
| geno3=(C;C)
| CEU | 0.0 | 8.1 | 91.9
| HCB | 25.5 | 38.7 | 35.8
| JPT | 17.0 | 46.4 | 36.6
| YRI | 7.5 | 46.3 | 46.3
| ASW | 3.5 | 47.4 | 49.1
| CHB | 25.5 | 38.7 | 35.8
| CHD | 25.9 | 54.6 | 19.4
| GIH | 4.0 | 29.7 | 66.3
| LWK | 13.8 | 34.9 | 51.4
| MEX | 7.0 | 40.4 | 52.6
| MKK | 5.8 | 38.1 | 56.1
| TSI | 2.0 | 14.7 | 83.3
| HapMapRevision=28
}}
[[rs1801270]] is a SNP known as p21 codon 31, although the gene now known to code for the p21 protein is termed [[CDKN1A]], and has also been known as WAF1 and CIP1. Along with p53 codon 72 ([[rs1042522]]), it is one of the best studied SNPs due to its role in increased tumor susceptibility (and thus [[cancer]]). 

A study of ~150 [[lung cancer]] patients in Sweden found that the [[rs1801279]](A) allele, encoding the amino acid Arg at codon 31, represented the risk allele (odds ratio 1.7, CI: 1.0-2.9), compared to healthy individuals. The difference was even more striking when compared to patients with [[chronic obstructive pulmonary disease]] (COPD), in which case the odds ratio was over 5.{{PMID|8807325}}

{{omim
|desc=CIP1/WAF1 TUMOR-ASSOCIATED POLYMORPHISM 1
|id=116899
|rsnum=1801270
|variant=0001
}}

{{PMID Auto
|PMID=19505915
|Title=Association of Genetic Polymorphisms, mRNA Expression of p53 and p21 with Chronic Benzene Poisoning in a Chinese Occupational Population
}}

{{PMID Auto
|PMID=20126416
|Title=Identification of single nucleotide polymorphisms in the p21 (CDKN1A) gene and correlations with longevity in the Italian population
|OA=1
}}

{{ClinVar
|rsid=1801270
|Reversed=0
|FwdREF=C
|FwdALT=A
|REF=C
|ALT=A
|RSPOS=36651971
|CHROM=6
|GMAF=0.2468
|dbSNPBuildID=89
|SSR=0
|SAO=1
|VP=0x05036800000015051f110100
|GENEINFO=CDKN1A:1026
|GENE_NAME=CDKN1A
|GENE_ID=1026
|WGT=0
|VC=SNV
|CLNALLE=1
|CLNHGVS=NC_000006.11:g.36651971C>A
|CLNORIGIN=1
|CLNSIG=2
|Tags=PM;PMC;S3D;SLO;VLD;G5;HD;GNO;KGPhase1;KGPilot123;KGPROD;OTHERKG;PH3;LSD;OM
|CAF=0.753; 0.247
|CLNACC=RCV000019125.1
|CLNDBN=CIP1/WAF1 TUMOR-ASSOCIATED POLYMORPHISM 1
|CLNSRC=OMIM Allelic Variant
|CLNSRCID=116899.0001
|COMMON=1
|Disease=CIP1/WAF1 TUMOR-ASSOCIATED POLYMORPHISM 1
}}

{{PMID Auto
|PMID=15878916
|Title=Genetic polymorphisms of p21 are associated with risk of squamous cell carcinoma of the head and neck.
}}

{{PMID Auto
|PMID=16111488
|Title=Phosphorylation states of cell cycle and DNA repair proteins can be altered by the nsSNPs.
|OA=1
}}

{{PMID Auto
|PMID=17293864
|Title=A common coding variant in CASP8 is associated with breast cancer risk.
}}

{{PMID Auto
|PMID=17459456
|Title=A common variant of the p16(INK4a) genetic region is associated with physical function in older people.
|OA=1
}}

{{PMID Auto
|PMID=18174243
|Title=Association of single-nucleotide polymorphisms in the cell cycle genes with breast cancer in the British population.
|OA=1
}}

{{PMID Auto
|PMID=18191955
|Title=Correlating observed odds ratios from lung cancer case-control studies to SNP functional scores predicted by bioinformatic tools.
|OA=1
}}

{{PMID Auto
|PMID=18805939
|Title=Functional genetic polymorphisms and female reproductive disorders: part II--endometriosis.
|OA=1
}}

{{PMID Auto
|PMID=19224585
|Title=Genotype and haplotype analysis of cell cycle genes in sporadic colorectal cancer in the Czech Republic.
}}

{{PMID Auto
|PMID=19237173
|Title=Bcl2 -938C/A polymorphism carries increased risk of biochemical recurrence after radical prostatectomy.
}}

{{PMID Auto
|PMID=19258477
|Title=Candidate gene analysis using imputed genotypes: cell cycle single-nucleotide polymorphisms and ovarian cancer risk.
|OA=1
}}

{{PMID Auto
|PMID=19367277
|Title=Genetic polymorphisms in DNA repair and damage response genes and late normal tissue complications of radiotherapy for breast cancer.
|OA=1
}}

{{PMID Auto
|PMID=19750108
|Title=Decreased PM10 exposure attenuates age-related lung function decline: genetic variants in p53, p21, and CCND1 modify this effect.
|OA=1
}}

{{PMID Auto
|PMID=20127253
|Title=The role of TP53 and p21 gene polymorphisms in breast cancer biology in a well specified and characterized German cohort.
}}

{{PMID Auto
|PMID=20433229
|Title=P21(waf1/cip1) gene polymorphisms and possible interaction with cigarette smoking in esophageal squamous cell carcinoma in northeastern Iran: a preliminary study.
}}

{{PMID Auto
|PMID=20452958
|Title=Single-nucleotide polymorphisms in the p53 signaling pathway.
|OA=1
}}

{{PMID Auto
|PMID=20979563
|Title=MDM2 and CDKN1A gene polymorphisms and risk of Kaposi's sarcoma in African and Caucasian patients.
}}

{{GET Evidence
|gene=CDKN1A
|aa_change=Ser31Arg
|aa_change_short=S31R
|impact=pathogenic
|qualified_impact=Insufficiently evaluated pathogenic
|inheritance=unknown
|quality_scores=Array
|dbsnp_id=rs1801270
|overall_frequency_n=1427
|overall_frequency_d=10758
|overall_frequency=0.132645
|n_genomes=14
|n_genomes_annotated=0
|n_haplomes=15
|n_articles=0
|n_articles_annotated=0
|in_omim=Y
|nblosum100=3
|autoscore=2
|webscore=N
|summary_short=Appears to be involved in tumor development, based on frequency of variant in tumor cell lines.
}}

{{PMID Auto
|PMID=23231583
|Title=Association of p21 SNPs and risk of cervical cancer among Chinese women
|OA=1
}}

{{on chip | 23andMe v1}}
{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | Affy GenomeWide 6}}
{{on chip | FTDNA2}}
{{on chip | Illumina Human 1M}}