Here, we have investigated the association of five markers [rs3735653 (C/T) in exon 1; rs34808376 (GC/-) and rs6150410 (CGCATCCCC/-) in promoter region; rs1861972 (A/G) and rs1861973 (C/T) in the intron] of the gene with autism and ASD in Indian population using family-based approach.
The haplotype A-C of rs1861972 and rs1861973 is the core element of the observed haplotype association in this study, which plays a role as a protective factor against autism; in addition, the haplotype G-A-C is less frequent in male cases compared to controls (38.64 vs. 52.51%), which plausibly modulate disease vulnerability to autism.
Since the associated SNPs were in high linkage disequilibrium and shared similar minor allele frequencies, we chose to test whether one of the SNPs (rs1861972) was associated with autism in three recruiting sites from the NIH Collaborative Programs of Excellence in Autism (CPEA) network.
Our previous research involving 167 nuclear families from the Autism Genetic Resource Exchange (AGRE) demonstrated that two intronic SNPs, rs1861972 and rs1861973, in the homeodomain transcription factor gene ENGRAILED 2 (EN2) are significantly associated with autism spectrum disorder (ASD).
Two intronic SNPs (rs1861972 and rs1861973) demonstrated significant association with autism (rs1861972, P=0.0018; rs1861973, P=0.0003; haplotype, P=0.000005).