Young people living with a genetic alteration that increases the risk of psychiatric disorders have markedly different brain activity during sleep.
The brain activity patterns during sleep shed light on the neurobiology behind a genetic condition called 22q11.2 Deletion Syndrome (22q11.2DS) and could be used as a biomarker to detect the onset of neuropsychiatric disorders in people with 22q11.2DS.
Caused by a gene deletion of around 30 genes on chromosome 22, 22q11.2DS occurs in one in 3000 births. It increases the risk of intellectual disability, autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD) and epileptic seizures. It is also one of the largest biological risk factors for schizophrenia. However, the biological mechanisms underlying psychiatric symptoms in 22q11.2DS are unclear.
The team recorded sleep EEG over one night in 28 young people aged six to 20-years old with the chromosome deletion and in 17 unaffected siblings. They measured correlations between sleep EEG patterns and psychiatric symptoms, as well as performance in a recall test the next morning. They found that the group with 22q11.2DS had significant alterations in sleep patterns including a greater proportion of N3 NREM sleep (slow-wave sleep) and lower proportions of N1 (the first and lightest sleep stage) and rapid eye movement (REM) sleep, compared with their siblings.
Paper: Donnelly N et al. (2022). Sleep EEG in young people with 22q11.2 deletion syndrome: a cross-sectional study of slow-waves, spindles and correlations with memory and neurodevelopmental symptoms. eLife.