Schizophrenia in relation with coronavirus SARS-CoV2 infection-an epigenetic explanation

Besides the biological effects of COVID-19, SARS CoV2 infection can increase the risk of schizophrenia. Schizophrenia is a chronic psychiatric condition that affects a person’s thinking, feeling, and behaviour. The exact causes of schizophrenia are unknown. Epigenetic mechanisms, mediating environmental factors to gene expression without directly affecting the DNA sequence, are related in schizophrenia. Machine learning (ML) methods are used in genomics studies for elucidation of three-dimensional structure of chromatin in genome. In chromatin, the formation of loop in 3D structure, controls the expression of specific genes in transcription and replication level. There is a 100% sequence similarity between SARS CoV2 and human genome for seventy-one nucleotide sequence in chromosome 2. This short stretch of nucleotide sequence has been thoroughly analyzed with the help of UCSC Genome Brower. A few machine learning models for construction of 3D structure of human genome for this specific chromosomal region have been explored. In the specific chromosomal region, the presence of a protein coding gene (KCNJ3), enhancer, promoter and LTR region are identified. With the help of machine learning methods, the loop formation on the genome structure has been confirmed. Topologically Associating Domains (TADs) in this specific chromosomal region are also predicted. The loop formation along the chromosomal region facilitates the binding of RNA polymerase II and CTCF in the promoter region of KCNJ3 gene. During transcription of KCNJ3 gene, epigenetic control of this gene expression occurs through acetylation in histone protein present in nucleosome complex. Thus, the rate of gene expression of KCNJ3 gene increases, which rises the K+ concentration inside the cells, resulting in schizophrenia in COVID-19 patients.