Related Experiment Video
Updated: May 8, 2026

Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants
Published on: February 21, 2015
The penetrance of copy number variations for schizophrenia and developmental delay
George Kirov1, Elliott Rees1, James T R Walters1
1Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom.
Background:
Several recurrent copy number variants (CNVs) have been shown to increase the risk of developing schizophrenia (SCZ), developmental delay (DD), autism spectrum disorders (ASD), and various congenital malformations (CM). Their penetrance for SCZ has been estimated to be modest. However, comparisons between their penetrance for SCZ or DD/ASD/CM, or estimates of the total penetrance for any of these disorders have not yet been made.
Methods:
We use data from the largest available studies on SCZ and DD/ASD/CM, including a new sample of 6882 cases and 6316 controls, to estimate the frequencies of 70 implicated CNVs in carriers with these disorders, healthy control subjects, and the general population. On the basis of these frequencies, we estimate their penetrance. We also estimate the strength of the selection pressure against CNVs and correlate this against their overall penetrance.
Results:
The rates of nearly all CNVs are higher in DD/ASD/CM compared with SCZ. The penetrance of CNVs is at least several times higher for the development of a disorder from the group of DD/ASD/CM. The overall penetrance of SCZ-associated CNVs for developing any disorder is high, ranging between 10.6% and 100%.
Conclusions:
CNVs associated with SCZ have high pathogenicity. The majority of the increased risk conferred by CNVs is toward the development of an earlier-onset disorder, such as DD/ASD/CM, rather than SCZ. The penetrance of CNVs correlates strongly with their selection coefficients. The improved estimates of penetrance will provide crucial information for genetic counselling.
Related Concept Videos
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Biological Causes of Schizophrenia
Genetic Factors in Schizophrenia
The genetic basis of schizophrenia is strongly supported by family and twin studies.
Single Nucleotide Polymorphisms-SNPs
Genomic Imprinting and Inheritance
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
Psychosis: Pathophysiology of Schizophrenia and Other Psychotic Disorders
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within the...
Principles of Pharmacogenetics: Types of Genetic Variants

