{{Rsnum
|rsid=16990018
|Gene=PRNP
|Chromosome=20
|position=4699732
|Orientation=plus
|ReferenceAllele=A
|MissenseAllele=G
|GMAF=0.01882
|Summary=Codes for Prion Protein codon 171
|geno1=(A;A)
|geno2=(A;G)
|geno3=(G;G)
|Gene_s=PRNP
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
}}{{ population diversity
| geno1=(A;A)
| geno2=(A;G)
| geno3=(G;G)
| CEU | 100.0 | 0.0 | 0.0
| HCB | 97.1 | 2.9 | 0.0
| JPT | 100.0 | 0.0 | 0.0
| YRI | 87.7 | 12.3 | 0.0
| ASW | 84.2 | 12.3 | 3.5
| CHB | 97.1 | 2.9 | 0.0
| CHD | 0.0 | 0.0 | 0.0
| GIH | 99.0 | 1.0 | 0.0
| LWK | 80.0 | 19.1 | 0.9
| MEX | 98.3 | 1.7 | 0.0
| MKK | 0.0 | 0.0 | 0.0
| TSI | 98.0 | 2.0 | 0.0
| HapMapRevision=28
}}{{omim
|desc=SPONGIFORM ENCEPHALOPATHY WITH NEUROPSYCHIATRIC FEATURES
|id=176640
|rsnum=16990018
|variant=0018
}}
{{ neighbor
| rsid = 1799990
| distance = 127
}}
{{ neighbor
| rsid = 28933385
| distance = 86
}}

{{ClinVar
|rsid=16990018
|Reversed=0
|FwdREF=A
|FwdALT=G
|REF=A
|ALT=G
|RSPOS=4680378
|CHROM=20
|GMAF=0.0188
|dbSNPBuildID=123
|SSR=0
|SAO=1
|VP=0x050368000000150517110100
|GENEINFO=PRNP:5621
|GENE_NAME=PRNP
|GENE_ID=5621
|WGT=0
|VC=SNV
|CLNALLE=1
|CLNHGVS=NC_000020.10:g.4680378A>G
|CLNSRC=GeneReviews; OMIM Allelic Variant
|CLNORIGIN=1
|CLNSRCID=NBK1229; 176640.0018
|CLNSIG=2
|CLNCUI=C1847650; C0162534
|CLNDBN=Spongiform encephalopathy with neuropsychiatric features; Genetic prion diseases
|Disease=Spongiform encephalopathy with neuropsychiatric features; Genetic prion diseases
|CLNACC=RCV000014348.11; RCV000020247.1
|Tags=PM;PMC;S3D;SLO;VLD;G5;HD;GNO;KGPhase1;KGPROD;OTHERKG;PH3;LSD;OM
|CAF=0.9812; 0.01882
|CLNDSDB=MedGen:OMIM; GeneReviews:MedGen
|CLNDSDBID=C1847650:606688; NBK1229:C0162534
|COMMON=1
}}

The importance of this codon has been reclassified based on further research. Normally Asn, the Asn171Ser variant was identified in a patient with [[Prion disease]], {{PMID|9384372}}, and further research indicated that it may be associated with temporal lobe epilepsy {{PMID|15304595}}. 

However, more recent research {{PMID|20583301}} has indicated that the N171S variant is present in healthy members of numerous populations, reaching penetrance of 11% in Biaka Pygmies and 5% in Jamaicans. Thus this polymorphism is considered of unknown significance.

{{on chip | 23andMe v1}}
{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | HumanOmni1Quad}}
{{on chip | Illumina Human 1M}}