August 10, 2007

Advancements In Understanding of One Schizophrenia Risk Gene

If you're interested in schizophrenia genetics and have a good science background - then this story is for you.

A new study that is published in the August issue of the Journal of Biological Chemistry, aims at increasing our knowledge on the genetics of schizophrenia. Though the study didn't find anything of immediate use to those with schizophrenia, they have set the ground for future genetic studies focused on genetic mutations found in patients with schizophrenia.

The study looked at how a genetic variation linked to schizophrenia from previous research, can cause a gene to be over expressed ("expressed" is when a gene creates a protein) in the human brain. The researchers adhere that the results are very complicated, and they have only now identified a few clues to what goes "wrong" with one genetic variation.

This research was inspired by previous studies on an Icelandic population. They found that "genetic variations in a DNA sequence close to a gene that produces a protein called Neuregulin 1 were associated with schizophrenia." Read this for some earlier information on Neuregulin 1 and schizophrenia. They later found in the brains of patients with schizophrenia that one variation increased the expression of Neuregulin 1 type 4.

The current study builds off of that research, and shows that Neuregulin 1 type 4 is brain specific - meaning only expressed in the brain, which is not the case with other types of neuregulin 1 that can be expressed in other parts of the body. They also found its 3.5 times more concentrated in fetal brains than in adult brains.

The research also highlights the pathway by which the genetic change occurs. The overproduction of Neuregulin 1 type 4 is caused by a promoter- which is a regulatory region of the DNA thast controls gene transcription. This is where the most future research may be focused. They already found that by altering this promoter, they could increase expressions of Neuregulin 1 type 4.

"For the first time, we have identified a promoter for the Neuregulin 1 gene and showed that the activity of that gene is altered by a single genetic variation in this promoter. These results will probably help us understand how DNA variations affect the function of this gene and lead to symptoms of schizophrenia."

Scientists Reveal Role of Mutation in Schizophrenia

Molecular Cloning of a Brain-specific, Developmentally Regulated Neuregulin 1 (NRG1) Isoform and Identification of a Functional Promoter Variant Associated with Schizophrenia.

Corresponding article, available full text PDF:
Insight into a Schizophrenia-related Mutation


Is this genetic feature gender specific? i.e., will it more commonly transfer from the male parent to the daughter, or the male parent to the son?

Posted by: Sue at August 15, 2007 01:29 AM

A 26 yr old woman has a mother with schizophrenia...what is her risk of having a child with schizophrenia? 3% or 7%?

Posted by: marisa at August 22, 2007 08:25 AM

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