Reelin blood levels as a marker of some types of autistic spectrum disorders (ASD)

Abstract

Objective: Reelin is a large glycoprotein secreted from specific neurons within the developing brain and encoded by RELN gene. Reelin regulates the signaling pathway of post-mitotic neurons to reach the proper layer of the central nervous system parenchyma, suggesting that deficiencies in the expression of RELN gene could play a role in the genesis of schizophrenia and ASD. Our aim is to find differences in the blood expression of Reelin between ASD patients and controls. Methods: A referral group of 30 ASD patients (27 boys and three girls) (Mean decimal age= 7.84±3.4 SD) were recruited from the neuropaediatric outpatient clinic of a secondary hospital. After meeting the criteria for ASD diagnosis, we invited the families to donate an aliquot from a blood test, required for clinical reasons. Samples were analyzed for plasma Reelin protein levels by Western blots. Other 10 patients (four boys and six girls) (Mean decimal age= 8.5±4.5 SD) suffering from minor neurologic symptoms such as headaches, dizziness, varied paroxysms and who also required a blood analysis (with normal results) accepted to join the study as controls. The data were tabulated and analyzed with the EpiInfo 7.2 statistical package, following the directions of the local ethics committee. Results: Sixteen patients of the ASD group (53.33%) showed Reelin values over the normal range, while only one from the control group did it (10%) being these differences statistically significant (OR=10.3; CI:1.15-91.6). Sixteen boys (56.61%) and one girl (11.11%) of the whole group showed elevated Reelin values near of statistical significance (OR=8.5; CI:0.95-76.6). Conclusion: In our series, patients suffering from ASD are 10 times more likely to present high Reelin blood levels than controls, suggesting the possibility that Reelin blood levels could be a suitable marker of some ASD types, although gender could play the role of a confusing factor.