Objectives: To assess the relationship between XCI patterns and alternative splicing, we evaluated the expression level of multiple alternative splicing transcripts for NLGN3, an X-linked autism gene, in autistic females with and without XIS.
Methods: Subjects were ascertained from the Autism Genetics Resource Exchange (AGRE). XCI status was determined using the Androgen Receptor gene assay on blood-derived genomic DNA. TaqMan gene expression experiments for multiple NLGN3 splice variants were conducted using RNA from AGRE lymphoblastoid cell lines. Exon boundaries/compositions of amplified products were confirmed by DNA sequencing.
Results: In addition to the two known NLGN3 variants, we identified three novel splice variants for this gene. A distinct, statistically significant pattern was detected in the expression level of examined alternatively spliced NLGN3 isoforms for autistic females with XIS compared to those without XIS and controls.
Conclusions: This is the first study to evaluate the expression level of NLGN3 at the alternative splicing level taking into consideration the X-inactivation status of autistic females. Our study indicates that NLGN3 undergoes complex splicing process resulting in multiple splice variants. Furthermore, our expression data demonstrates that autistic females with XIS may represent a more homogeneous subset of this highly heterogeneous population. Applying such a stratification method may provide a way to better understand underlying genetic and epigenetic mechanism in autism. Our study introduces a novel and effective method to connect different lines of genomic data in unraveling the etiology of this complex neurodevelopmental disorder.
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See more of: Biological Mechanisms