Rs793862, a SNP in the DCDC2 gene, is in a region that crops up in several independent studies as likely to associated with dyslexia. The risk allele in the Caucasian populations studied is (A).
One study reports that the odds ratio for rs793862 genotypes increases if calculated from subsets of more severely dyslexic individuals as compared to more heterogenous, larger groups of dyslexic individuals. The genotype relative risk (GRR) for rs793862(A;A) increased from 3.15 (95% CI 1.30-7.66; P=.011) for the larger group up to 5.40 (95% CI 1.27-23.01; P=.002) for the most severely affected group. [PMID 16385449]
Combined with another SNP marker in the DCDC2 gene, rs807701, the (haplotype) GRR also increased for the homozygous haplotype A-C, from 4.11 (95% CI 2.77-6.08; P<.0001) for the larger group, up to 11.13 (95% CI 6.32-19.60; P<.0001) for the most severely affected group. [PMID 16385449]
This SNP was also reported to be significantly associated in a linkage study of dyslexic individuals. [PMID 15138886]
[PMID 15717286] Strong evidence that KIAA0319 on chromosome 6p is a susceptibility gene for developmental dyslexia.
[PMID 19238550] The role of gene DCDC2 in German dyslexics.
[PMID 21881542] DCDC2 genetic variants and susceptibility to developmental dyslexia.
[PMID 25012462] The role of DCDC2 genetic variants and low socioeconomic status in vulnerability to attention problems