Copy Number Variations in the Brazilian High-Risk Cohort for Mental Conditions.

Abstract

Copy number variations (CNVs) are genetic variants with a known major impact on the development of mental health disorders (MHDs). Here, we aim to characterize CNVs in a Brazilian cohort regarding frequency and inheritance pattern and verify the impact of CNVs previously associated with MHDs on the risk of developing these disorders in the cohort. A total of 2,250 probands and 3,174 parents (897 trios) from the Brazilian High-Risk Cohort Study for Mental Conditions (BHRCS) were genotyped and CNVs were detected using PennCNV software. In total, 56.03% of the CNVs were inherited. Among the distinct CNVs, 96.15% were rare (frequency lower than 1% in the BHRCS). Duplications at 2q13 and 15q13.3 showed lower frequencies, while those at 2q11.2 and 16p11.2 exhibited higher frequencies in the BHRCS when compared to databases such as the Database of Genomic Variants (DGV) and the Genome Aggregation Database (gnomAD). Of 40 previously associated CNVs with MHDs, 18 were identified in the sample. While the 7q11.2 duplication has been considered protective for Schizophrenia, we identified that 7q11.2 deletion was protective for MHDs in BHRCS (p-value=0.033, OR=0.103). For the other CNVs, no statistical significance was identified, even with mild effect sizes. This is one of the largest CNV studies in a Brazilian sample and will be a valuable resource for future meta-analysis to advance the understanding of the genetics of MHDs, especially regarding diverse populations.