Genomic Analysis of Trichotillomania

Area of Science:

• Psychiatric Genetics
• Human Genetics
• Behavioral Science

Background:

• Trichotillomania (TTM) is a psychiatric disorder characterized by compulsive hair pulling and significant distress.
• Previous twin and family studies suggest a partial genetic basis for TTM.
• No genome-wide association studies (GWAS) have been conducted for TTM.

Purpose of the Study:

• To conduct the first formal genome-wide association study (GWAS) for TTM.
• To investigate the genetic underpinnings of TTM in European ancestry populations.
• To identify common and rare genetic variants associated with TTM.

Main Methods:

• A case-control study design was employed.
• Genotype array data from 101 European ancestry TTM cases and 488 controls were analyzed.
• Cases were recruited through web-based methods, support groups, and conferences.

Main Results:

• No common variants reached genome-wide significance for association with TTM.
• TTM cases exhibited a higher polygenic risk load for psychiatric disorders (p=0.008).
• Copy number variants (CNVs), including deletions in NRXN1, CSMD1, and 15q11.2, were detected and previously linked to neuropsychiatric disorders.

Conclusions:

• The findings support a significant role for genetics in the etiology of TTM.
• Larger sample sizes are needed to identify specific risk variations and genes for TTM.
• The presence of CNVs associated with neuropsychiatric disorders warrants further investigation in TTM.