TY - THES ID - 134831814 TI - Genome-wide association of global-to-local brain cortical thickness AU - Feng, Peiyan AU - Cleynen, Isabelle AU - Claes, Peter AU - KU Leuven. Faculteit Bio-ingenieurswetenschappen. Opleiding Master of Bioinformatics (Leuven) PY - 2021 PB - Leuven KU Leuven. Faculteit Bio-ingenieurswetenschappen DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:134831814 AB - In this thesis, we performed a genome-wide association study of the human brain cortical thickness, which is based on a data-driven, hierarchical global-to-local cortical segmentation. The UKB dataset of nearly 20,000 samples was used as a discovery cohort for training the segmentation and association tests. To gain insights into the genetic architecture of the cortical thickness, the univariant GWAS of the entire G2L segmentation was performed using PLINK by treating the thickness of each segment as an independent trait. And then, the result of GWAS was further analysed with FUMA, LDSC, to map the loci, perform the pathway enrichment and test the genetic correlation with other traits. To evaluate the G2L segmentation, we compare it with the traditional Desikan-Killiany atlas, the Glasser atlas and the Destrieux atlas, the Desikan-Killiany atlas-based GWAS study was also compared. The result shows that the cortical thickness's genetic architecture is highly polygenic, and the scope of effect of the variants also varies, from the global average thickness to the tiny segments. The results of the genetic correlation are also in general agreement with previous morphological studies. Compared to the traditional atlas, G2L segmentation offers a rather different segmentation method, providing a global-to-local perspective that captures more loci that are significantly associated with cortical thickness. ER -