{{Rsnum
|rsid=10248420
|Gene=ABCB1
|Chromosome=7
|position=87535670
|Orientation=plus
|GMAF=0.3476
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(A;A)
|geno2=(A;G)
|geno3=(G;G)
|Gene_s=ABCB1
}}{{ population diversity
| geno1=(A;A)
| geno2=(A;G)
| geno3=(G;G)
| CEU | 67.3 | 31.9 | 0.9
| HCB | 23.5 | 50.7 | 25.7
| JPT | 28.8 | 55.9 | 15.3
| YRI | 11.6 | 49.0 | 39.5
| ASW | 29.8 | 56.1 | 14.0
| CHB | 23.5 | 50.7 | 25.7
| CHD | 33.0 | 47.7 | 19.3
| GIH | 57.4 | 37.6 | 5.0
| LWK | 17.3 | 43.6 | 39.1
| MEX | 60.3 | 31.0 | 8.6
| MKK | 19.5 | 48.1 | 32.5
| TSI | 61.8 | 35.3 | 2.9
| HapMapRevision=28
}}[[rs10248420]] is a SNP in the [[ABCB1]] gene (also known as the MDR1 gene), which encodes a protein that transports certain molecules across the blood-brain barrier. SNPs in [[ABCB1]] may thus influence the intracerebral concentrations of certain drugs and thus their efficacy or potential for adverse side effects. [[rs10248420]] is one of 9 SNPs found within a tight linkage block (r<sup>2</sup> >= 0.8 ) such that the minor allele at any one of them predicts (with ~80%+ accuracy) that the other SNPs will also be the minor allele. The list of the 9 SNPs is shown below.

When treated for [[depression]] with substrates of the protein encoded by [[ABCB1]], carriers of one or two minor alleles at these [[ABCB1]] SNPs have been reported to respond better than non-carriers. The [[antidepressant]] drugs that are known to be substrates include [[citalopram]], [[paroxetine]], [[amitriptyline]], and [[venlafaxine]]. The relative odds of better response for [[rs10248420]](G) carriers is 7.72 (CI: 2.8-21.3, p=0.000065) based on a study of ~400 primarily Caucasian patients.{{doi|10.1016/j.neuron.2007.11.017}}

The 9 SNPs in the linkage block identified are {{doi|10.1016/j.neuron.2007.11.017}}:
* [[rs2235067]]
* [[rs4148740]]
* [[rs2032583]]
* [[rs4148739]]
* [[rs11983225]]
* [[rs2235040]]
* [[rs12720067]]
* [[rs7787082]]
* [[rs10248420]]

{{PMID|19107781}} [[rs10248420]] and [[rs2032583]] associated with colonic disease

{{ neighbor
| rsid = 2235040
| distance = 764
}}

{{PharmGKB
|RSID=rs10248420
|Name_s=
|Gene_s=ABCB1
|Feature=
|Evidence=PubMed ID:18215618
|Annotation=This variant is associated with differences in clinical efficacy of antidepressants, most likely by influencing their access to the brain.
|Drugs=amitriptyline; citalopram; paroxetine; venlafaxine
|Drug Classes=
|Diseases=Depression
|Curation Level=Curated
|PharmGKB Accession ID=PA161615698
}}

{{PMID|15197162|OA=1
}} Identifying candidate causal variants responsible for altered activity of the ABCB1 multidrug resistance gene.

{{GET Evidence
|impact=pharmacogenetic
|qualified_impact=Insufficiently evaluated pharmacogenetic
|inheritance=unknown
|quality_scores=Array
|dbsnp_id=rs10248420
|overall_frequency_n=42
|overall_frequency_d=128
|overall_frequency=0.328125
|n_genomes=28
|n_genomes_annotated=0
|n_haplomes=38
|n_articles=1
|n_articles_annotated=0
|in_pharmgkb=Y
|autoscore=1
|webscore=N
}}

{{PMID Auto
|PMID=22722500
|Title=Association study of 27 annotated genes for clozapine pharmacogenetics: validation of preexisting studies and identification of a new candidate gene, ABCB1, for treatment response.
}}

{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | FTDNA2}}
{{on chip | HumanOmni1Quad}}
{{on chip | Illumina Human 1M}}