In our lives there is a window of time that we all have gone through, but we know little about it yet: early pregnancy. Researchers have discovered a pair of genetic deletions associated with schizophrenia that are likely to occur during its formative period.
The discovery is Harvard Medical School Clinical Medical Scientist Eduardo Morley examined genetic data from around 25,000 blood samples, with or without schizophrenia.
The two genetic changes require further testing, but the findings say that schizophrenia seeds are not always inherited, but they may be acquired long before someone meets the world. It strengthens new ideas.
If so, it opens the door to early prevention more broadly.
Schizophrenia is a serious neurological disorder resulting from a complex mix of genetic and environmental factors; Childhood trauma Or it could be a viral infection Play a roleamplifies the risk of someone experiencing symptoms of delusional or disability thoughts in later years.
That affects 1 in 300 people It usually appears around the world in early adulthood. However, there is evidence suggesting that the physiology responsible for schizophrenia occurs as a result of early pregnancy or pregnancy complications.
In 2017, scientists studying a bundle of experimental cells that resemble small brains discovered evidence that confused brain cells can quickly divide, and premature brain cells can cause schizophrenia. did. And in 2021, researchers identified specific placenta genes that are active and associated with disorders during complex pregnancy.
In 2023, Maury and her colleagues identified two genes called NRXN1 and ABCB11. This appears to be related to schizophrenia when a copy of a gene disappears into the uterus.
“We see mutations that are not inherited from our parents.” I explained it Chris Walsh, senior author and geneticist at Boston Children’s Hospital, said at the time the study was published.
In NRXN1 and ABCB11, researchers found that change is called Copy number variationa type of genetic error that is replicated or deleted in this case by one person compared to the following person.
In rare cases, you can inherit copy number variations and contribute to Approximately 5% A case of schizophrenia. These so-called germ cell mutations appear in every cell in the body as they were written in the human genome before the fertilized eggs undergo initial division.
The study also suggests that four out of five cases of schizophrenia can be traced back to genes inherited by children’s parents, and a recent study added to the list of known genetic links. It’s there. Still, about 20% of cases still remain, without clear evidence of succession.
Of the two genes identified in this study, Maury and colleagues discovered a partial deletion of Nrxn1 in five cases of schizophrenia and found nothing in individuals not affected by the control cohort. That was it. This prevalence was much higher than that of a population-level database.
NRXN1 helped brain cells transmit signals and was previously associated with schizophrenia – when These mutations have been inherited.
If mutations are not inherited, but are acquired early or late, they are called Somatic mutations. When these occur after embryonic cells begin separate journeys to form different cells that go on to create an already complete human, they are passed to the progeny of the cell along with mutations.
Somatic mutations are therefore only seen in some somatic cells. For example, the brain and blood cells are not of nature. This is a type of Maury and colleagues of the NRXN1 mutation.
The second identified gene, ABCB11, is known to encode liver proteins, but the link to schizophrenia is less certain.
Maury and colleagues found deletion within the ABCB11 gene in another five cases of schizophrenia, but all of them did not respond to antipsychotics.
“That person came out of nowhere for us.” I said Maury from ABCB11. “There have been some studies linking mutations in this gene to treatment-resistant schizophrenia, but they are not strongly involved in schizophrenia itself.”
Researcher Conclusion These two gene changes “may contribute to small but important parts of the genetic structure of schizophrenia.”
More research is needed to understand how well it is.
This study was published in Cell genomics.
An earlier version of this article was published in July 2023.
