Integrative analysis of shared genetic pathogenesis by obsessive-compulsive and eating disorders

A number of common pathological features have been observed in obsessive-compulsive disorder (OCD) and eating disorders (EDs). The present study examined the association between OCD and EDs at the genetic level in order to gain an improved understanding of the shared genetic basis of the diseases and identify novel potential risk genes for the two diseases. An integrated analysis using large-scale disease-gene association data and gene expression data was conducted. Disease-gene association data were acquired from the Pathway Studio Mammalian database. Gene expression data were acquired from samples of 133 subjects, including 15 ED cases, 16 OCD cases and 102 normal controls. Genes associated with OCD and ED presented significant overlap (21 genes, P=6.70x10 ^-34 ), serving roles within multiple common genetic pathways (top 10 pathway enrichment P<4.30x10 ^-7 ) that were implicated in the two diseases. A genetic network of 17 genes was constructed, through which OCD and ED were observed to influence each other. Expression analysis revealed four novel common significant genes for OCD and ED (oxytocin receptor, glutamate decarboxylase 2, neuropeptide Y and glutamate ionotropic receptor kainate type subunit 3). These genes demonstrated a strong functional association with the two diseases. The results of the present study supported the presence of complex genetic associations between OCD and ED. Genes associated with one disease are worthy of further investigation as potential risk factors for the other. The findings of the present study may provide novel insights into the understanding of the pathogenesis of OCD and ED.