{{Rsnum
|rsid=2143340
|Gene=TTRAP
|Chromosome=6
|position=24658843
|Orientation=minus
|GMAF=0.1501
|Gene_s=TDP2
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(C;C)
|geno2=(C;T)
|geno3=(T;T)
}}{{ population diversity
| geno1=(C;C)
| geno2=(C;T)
| geno3=(T;T)
| CEU | 6.2 | 27.7 | 66.2
| HCB | 4.4 | 17.8 | 77.8
| JPT | 4.4 | 22.2 | 73.3
| YRI | 3.2 | 31.7 | 65.1
| ASW | 0.0 | 0.0 | 0.0
| CHB | 4.4 | 17.8 | 77.8
| CHD | 0.0 | 0.0 | 0.0
| GIH | 0.0 | 0.0 | 0.0
| LWK | 0.0 | 0.0 | 0.0
| MEX | 0.0 | 0.0 | 0.0
| MKK | 0.0 | 0.0 | 0.0
| TSI | 0.0 | 0.0 | 0.0
| HapMapRevision=28
}}{{PMID|18829873}} genetic risk for poor reading performance.

Rs2143340, a SNP in the [[TTRAP]] gene, is in a region that crops up in several independent studies as likely to associated with [[dyslexia]]. The risk allele in the US/UK Caucasian populations studied is (C), and it is indicative of a risk haplotype found in ~18% of the general population but up to ~28% of severely dyslexic individuals. {{PMID|15514892|OA=1
}}

It is not thought that [[rs2143340]] is a functional SNP; instead, it marks the haplotype known as [[rs4504469]]-[[rs2038137]]-[[rs2143340]] "1-1-2" since the other two SNPs are the common forms whereas the significant form for [[rs2143340]] is the rare form. The functional effect of this haplotype appears to be on the [[KIAA0319]] gene, in that [[KIAA0319]] gene activity associated with the 1-1-2 risk haplotype is 40% lower than for other haplotypes, and other genes aren't noticeably affected. {{PMID|16600991}} {{PMID|18829873}}

{{omim
|desc=KIAA0319 GENE; KIAA0319
|id=609269
|rsnum=2143340
}}

{{omim
|id=600202
|rsnum=2143340
}}

{{PMID Auto
|PMID=15717286
|Title=Strong evidence that KIAA0319 on chromosome 6p is a susceptibility gene for developmental dyslexia.
|OA=1
}}

{{PMID Auto
|PMID=16385449
|Title=Strong genetic evidence of DCDC2 as a susceptibility gene for dyslexia.
|OA=1
}}

{{PMID Auto
|PMID=17597587
|Title=A haplotype spanning KIAA0319 and TTRAP is associated with normal variation in reading and spelling ability.
}}

{{PMID Auto
|PMID=19325871
|Title=A common variant associated with dyslexia reduces expression of the KIAA0319 gene.
|OA=1
}}

{{on chip | 23andMe v1}}
{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | FTDNA2}}
{{on chip | HumanOmni1Quad}}