A Family Based Study Implicates Solute Carrier Family 1–Member 3 (SLC1A3) Gene in Attention-Deficit/Hyperactivity Disorder

Background The glutamatergic system, the major excitatory neurotransmitter system in the central nervous system (CNS) has been proposed as contributing a possible role in the etiology of attention deficit hyperactivity disorder (ADHD). This is based upon observations from animal, neuroimaging, neuroanatomical and neuropsychological studies. Genes related to glutamate function are therefore good functional candidates for this disorder. The SLC1A3 (Solute Carrier Family 1, member 3) gene encodes a glial glutamate transporter which maps to chromosome 5p12, a region of linkage that coincides in two published ADHD genome scans so far. SLC1A3 is thus both a functional and positional candidate gene for ADHD. Methods We have undertaken detailed association analysis of SLC1A3 using a multi-stage approach for candidate gene analysis. Results In a family-based sample (n = 299) we found a significant association between marker rs2269272 (p = .007) and ADHD. Two, two-marker haplotypes, rs2269272/rs3776581 (p = .016) and rs2269272/rs2032893 (p = .013) also yielded evidence of association. Conclusions The results of our study suggest that genetic variation in SLC1A3 may contribute to susceptibility to ADHD.