(HealthDay News) – Specific genetic variants and features may be factors for Tourette’s syndrome and obsessive-compulsive disorder (OCD).

Jeremiah M. Scharf, MD, PhD, from the Center for Human Genetics Research in Boston, and colleagues conducted a GWAS of Tourette’s syndrome using 1,285 cases and 4,964 ancestry-matched controls of European ancestry. In a primary meta-analysis of the data, the researchers found that no markers achieved a genome-wide threshold of significance, but the top signal was observed in rs7868992 on chromosome 9q32 within COL27A1. An additional 211 cases and 285 controls from Latin American population isolates were included in a secondary analysis, which also identified rs7868992 as the top signal.

S. Evelyn Stewart, MD, also from the Center for Human Genetics Research in Boston, and colleagues examined genetic variation predisposing to OCD in a set of affected individuals, a subset of their parents, and unselected controls. A total of 1,465 cases with OCD and 5,557 ancestry-matched controls, including 400 complete trios, were analyzed. The researchers found that, in the ancestry-stratified case-control analysis, the lowest two P-values were located within DLGAP1, a member of the neuronal postsynaptic density complex. In the trio analysis, genome-wide significance was exceeded by rs6131295, located near BTBD3, but this variant lost significance when the trios were meta-analyzed with the case-control samples. There was significant enrichment of methylation of quantitative trait loci (QTLs) and frontal lobe expression QTLs.

“[These findings suggest that] these top signals may have a broad role in gene expression in the brain, and possibly in the etiology of OCD,” Stewart and colleagues write.

Several authors of both studies disclosed financial ties to the pharmaceutical and medical technology industries.

Abstract – Scharf
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Abstract – Stewart
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