The cerebellum is an important function for cognition, emotion, and function in the brain. More and more evidence is pointing to the cerebellum to explain various psychopathologies. The loss of cerebellum volume is commonly reported in those with schizophrenia, bipolar disorder, and depression and their unimpacted relatives. According to studies on twins, it is also believed that volume loss is hereditary. Thus, many scientists believe cerebellum volume loss is genetic; however, there is still much to learn.
Researchers conducted a genome-wide association study (GWAS) of total cerebellar volume and underlying cerebellar lobe volumes in 33,265 UK-Biobank participants. This study utilizes T1-weighted structural brain magnetic resonance imaging (MRI) image-derived phenotypes (IDPs) data for ~40,000 individuals from UK Biobank. The research group accessed the data in two batches, each containing approximately half of the total sample (wave 1 and wave 2). The meta-analysis of two waves’ GWAS identified 33 conditionally independent index SNPs associated with total cerebellar volume. All index SNPs in each wave were present within the 33 meta-GWAS index SNPs, all 33 meta-GWAS index SNPs were at least nominally significant in each wave, and with all showing the same direction of effect across waves. These include rs7530673, rs1278519, rs4148155 in the ABCG2 gene, rs13135092 in the SLC39A8 gene, rs1800562 in the HFE gene, rs72754248 in the PAPPA, rs17220352 in the ASTN2, rs3118634 in the PTPA, rs5742632 in the LINC02456, and rs703545 in the LOC105369944 gene. In analysis, they found significant genetic correlations between total cerebellar volume and brainstem, pallidum, and thalamus volumes. But they did not find significant correlations with specific psychiatric conditions.
While this study can tell us a lot, it is limited because it does not represent the full UK population and is biased from a socioeconomic and demographic perspective. Additionally, because participants were predominantly British and Irish, it’s unclear if the results would be the same for other ancestries. If you would like to know more about this research, you can read the study here:
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