Research on the causes of schizophrenia is ongoing and multifaceted, although evidence from earlier studies suggests that there are hereditary risk factors for schizophrenia.
Between 60% and 80% of schizophrenia cases are heritable, according to research. It does not always follow that you will acquire schizophrenia just because a family member does.
Continue reading to discover more about the interactions between genetic and environmental variables that might increase a person’s risk of developing this mental illness.
Genetic Roots
The Complex Genetic Factors in Schizophrenia
Schizophrenia is polygenic – caused by multiple genes interacting, not a single gene defect.
Through genome studies, researchers have identified over 100 genomic regions connected to schizophrenia risk. Each variant contributes a small increase in vulnerability.
The identified loci contain over 600 genes affecting things like:
- Immune function.
- Dopamine signaling.
- Calcium channels.
- Glutamate receptors.
However, it’s complicated. A locus refers to a position on a chromosome where a gene is located. Just because a gene sits in an implicated locus does not prove direct involvement.
In summary, schizophrenia arises from a complex interplay of numerous genetic variants. Specific genes have been identified that may raise risk, but they only tell part of the story. More research is underway to unravel the intricate genetic factors underlying schizophrenia.
Deletion of 22q11.2
Duplications, deletions, and microdeletions are among the genetic changes linked to schizophrenia. The 22q11.2 deletion syndrome is one of the most researched deletions with a high prevalence of schizophrenia. According to estimates, schizophrenia affects roughly 22% of those who have this deletion.7
Version of DRD2
The His313 polymorphism in the DRD2 gene has been related to schizophrenia, according to research.8The signaling of dopamine receptors is regulated by this gene.
Version of ZNF804A
Researchers have identified the zinc finger protein gene ZNR804A, most active during pregnancy, as a risk gene for schizophrenia. This gene’s rs1344706 polymorphism connects to schizophrenia vulnerability.
The Role of Genetics in Schizophrenia
Schizophrenia has a strong genetic component, with estimates of heritability between 60-80%. Having a close relative with schizophrenia significantly increases your risk.
- If one parent has schizophrenia, your risk is 10x higher than the general population (1%).
- With two parents, the risk is 40x higher.
Twin studies reveal insight into the genetic influence. Identical twins share 100% of DNA, while fraternal twins share 50%.
- In a 2018 Danish study, 33% of identical twins both had schizophrenia, compared to 7% of fraternal twins.
- Researchers estimated heritability at 79% in this study.
However, the 33% concordance in identical twins shows factors besides genetics also impact schizophrenia risk.
Most genetic schizophrenia research has used European-ancestry participants. Findings may not apply evenly across global populations. Genetic studies need more diversity in their participant samples.
While genetics play a key role, schizophrenia risk involves a complex interplay of genetic vulnerability and environmental factors.
Schizophrenia: The Role of Genes vs. Environment
While genetics play a significant role, genes alone do not determine who will develop schizophrenia. Environmental factors also impact risk.
Genome studies explain some but not all cases. Researchers believe gene-environment interactions are important.
Someone may have a genetic vulnerability, but environmental factors still trigger schizophrenia even with genetic risks present.
Known environmental risks include:
- Pregnancy/birth complications.
- Viral infections.
- Older parental age.
- Trauma.
- Social disadvantage.
- Isolation.
- Immigration.
- Urban living.
- Substance use.
The causes involve a complex interplay between genetic and environmental factors. Scientists need to conduct more research on both fronts.
Ultimately, we cannot yet predict schizophrenia based on genetics alone. Both nature and nurture contribute to risk. Ongoing studies continue to uncover the genetic and environmental underpinnings of schizophrenia to improve treatment.
Get Help for Schizophrenia
Lastly, If you or a loved one is dealing with schizophrenia, support and treatment can help manage symptoms. The caring professionals at Kazmo Brain Center specialize in schizophrenia treatment using evidence-based therapies and medications. Our integrated care addresses both mental and physical wellbeing. Contact us today to learn more about our schizophrenia programs. With compassionate support and the latest therapies, recovery is possible.
