# The interplay between genomic copy number variants, sleep, and cognition in the general population

## TL;DR

This study explores how genomic copy number variants affect sleep and cognition in the general population, finding a U-shaped pattern in their effects.

## Contribution

The study reveals a U-shaped relationship between CNV burden and sleep duration, and links it to cognitive performance.

## Key findings

- CNVs with more intolerant genes show a U-shaped effect on sleep duration.
- Sleep duration only marginally mediates the link between CNVs and cognitive performance.
- CNVs do not increase insomnia risk but are associated with cognitive decline.

## Abstract

Genomic Copy Number variants (CNVs) increase risk for neurodevelopmental disorders (NDDs) and affect cognition, but their impact on sleep remains understudied despite the well-established link between sleep disturbances, NDDs, and cognition.

We investigated the relationship between CNVs, sleep traits, cognitive ability, and executive function in 498,852 individuals from an unselected population in the UK Biobank.

We replicated the U-shape relationship between measures of cognitive ability and sleep duration. The effects of CNVs on sleep duration were evident at the genome-wide level; CNV-burden analyses showed that overall, CNVs with an increasing number of intolerant genes were associated with increased or decreased sleep duration in a U-shape pattern (p < 2e−16), but did not increase risk of insomnia. Sleep duration only marginally mediated the robust association between CNVs and poorer cognitive performance, suggesting that sleep and cognitive phenotypes may result from pleiotropic effects of CNVs with minimal causal relationship.