Objectives: Study the genetic association between BDNF and NRCAM polymorphisms with autism in a French population.
Methods: The BDNF gene is located on chromosome 11p13 and corresponds to one haplotype block only. While the NRCAM gene is mapped on chromosome 7q31.1-q31.2 region and is encompassed by several haplotype block We performed a case-control study by genotyping two SNPs (the missense rs6265 and rs11030121) within BDNF gene, and the missense rs6958498 within NRCAM gene, using TaqMan® SNP Genotyping Assays, on 84 French autistic patients and 143 healthy controls matching for the geographic origin. Hardy-Weinberg equilibrium of SNPs was checked by using Haploview software. Distributions of alleles, genotypes and carriers were compared between patients and controls by crosstabs analysis.
Results: Each SNP followed the Hardy-Weinberg equilibrium. No significant difference of frequency for rs6265 or rs11030121 was found in patients compared to controls (81% versus 83% and 68% versus 72%, respectively for each major allele). Furthermore, no difference of distribution was found with the genotypes and carriers of each SNPs, nor with the haplotype rs6265-rs11030121. In contrast, we found a trend for association between NRCAM polymorphism and autism with an overrepresentation of the C allele (84.7% versus 77.3%, Fisher’s exact test 2-sided p=0.1), corresponding to the proline amino acid.
Conclusions: This genetic analysis, on a population originating from