Selected Research on Twins and the Immune System

This is getting to one of the many reasons PSYCHIATRIC DISORDERS have been so hard to  CRACK from a scientific point of view.

People have thought "MENTAL ILLNESS" was BIOLOGICAL of a sort for  a long time.

A Long Time being THOUSANDS of years --- there were also DEMONS & DEVILS.  More recently, certainly in the 20s and 30s people thought "MENTAL ILLNESS" was HERITABLE.

                 But one of the BIG PROBLEMS came when one discovered that TWIN STUDIES didn't CONFIRM this the way we thought it would be confirmed if it was STRICTLY HERITABLE --- and we were largely focused on the BRAIN to the best of our ability.

                  Some people had thought the IMMUNE SYSTEM might play a role --- BUT they were not able to confirm that the way it is being confirmed in the 21st Century.  

                    So in the 20th Century researchers were looking at the BRAIN, GENETICS and "TRAUMA," especially CHILDHOOD TRAUMA because that was recognized as influencing BRAIN DEVELOPMENT when it came to PSYCHIATRIC DISORDERS.

​                    It was also recognized that some people might be more genetically susceptible to PTSD.

                     When we're looking at IMMUNITY were looking at

• Genetics
• Maternal Immune Activation during Pregnancy
• Innate Immunity:  Immunity One is Born with
• Adaptive Immunity:  the Immune System is Adapting over the course of the person's life, and
• Epigenetics

                        At this time -- to me, PSYCHIATRIC DISORDERS appear to be a subset of AUTO-IMMUNE and CHRONIC INFLAMMATORY DISEASES with GENETIC, ENVIRONMENTAL and EPIGENETIC FACTORS.   ​

​Lessons learned from twins in autoimmune and chronic inflammatory diseases (2017)

Affiliations

1Division of Rheumatology and Clinical Immunology, Humanitas Research Hospital, Rozzano, Milan, Italy.
2Italian Twin Registry, Centre for Behavioural Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
3Division of Rheumatology and Clinical Immunology, Humanitas Research Hospital, Rozzano, Milan, Italy; BIOMETRA Department, University of Milan, Milan, Italy. 

Further, concordance rates in monozygotic twins should be compared to those in dizygotic twins, which share 50% of their genes, as in regular siblings, but also young-age environmental factors. ...These observations are necessary to interpret data gathered by genome …

​The Epigenetics of Lupus Erythematosus (2020)

Affiliations

1Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
2Division of Pediatric Immunology and Allergy, Joe DiMaggio Children's Hospital, Hollywood, FL, 33021, USA.
3Division of Rheumatology, Allergy and Clinical Immunology, University of California Davis, Davis, CA, 95616, USA.
4Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, Second Xiangya Hospital, Central South University, Changsha, Hunan, China. 

However, increasing evidence has shown that environment factors, genetic susceptibilities, and epigenetic regulation contribute to abnormalities in the immune system. ...However, genetics cannot explain the high discordance of lupus incidence in homozygous twins …

Therefore, this chapter will summarize the up-to-date progress on epigenetics regulation in lupus, in order to broaden our understanding of lupus and discuss the potential roles of epigenetic regulations for clinical applications.

Epigenetics of Autism Spectrum Disorder.  (2017)

Affiliations

1Program in Genetics and Genome Biology, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada.
2Program in Genetics and Genome Biology, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada. 
3Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada. 
4Department of Paediatrics, University of Toronto, Toronto, ON, M5S 1A1, Canada. 
5Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada. 

The etiopathogenesis of ASD is known to be complex, including genetic, environmental and epigenetic factors.

Normal epigenetic marks modifiable by both genetics and environmental exposures can result in epigenetic alterations that disrupt the regulation of gene expression, negatively impacting biological pathways important for brain development.