The Relationship Between Gene Mutation and Dementia

Recently, a thesis published in nature revealed that how does the genetic mutation lead to amyotrophic lateral sclerosis(ALS)and frontotemporal dementia (FTD). The researchers found that the change of C9orf72 will make RNA molecular disrupt the transport of protein. This will lead to a traffic jam in the molecular of external cell nucleus of brain and make it function abnormally.
One of the researchers, Jeffrey Rothstein, pointed that 40% genetic ALS and 25% genetic FTD is related to this mutation. The neurocyte of Patients with ALS or FTD often degenerate as time goes on. For FTD patients, this damage will make them gradually lose the ability of language control and emotional control. And patients will gradually lose the power of muscular control.
This mutation is a kind of repetition which called hexanucleotide repeat expansion (HRE). It is a repetition of six DNA nucleotides. In this article, researchers picked one important protein named RanGAP. In normal cells this RanGaP can transport molecule by connecting to the nuclear pore complex of cytoplasm. However, RanGap in FTD and ALS patients stay in the state of aggregation, and the nuclear pore complex also stops working. So researchers did another experiment. They add antisense oligodeoxynucleotide to a drosophila melanogaster and interdict the interaction between antisense oligodeoxynucleotide and RanGap, then they found the nuclear pore complex starting work again.
In fact, there is still no effective way for curing ALS and FTD, not to mention the prevention of the diseases. Scientists tried to explain this on many fields including genetic methods. This research provides another possibility for it and possibility for gene therapy. Gene therapy, what a wonderful idea! And more and more research on the relationship between gene and disease makes this become possible. Since the first adenosine deaminase deficiency patient was cured by gene therapy, scientists have spent a lot of money and energy on this field. Twenty-five years passed and the technology has changed. Now our research is facing the biggest challenge. One is the coming of big data. By this way researchers can find information more and more easily. For example, if they want to do Exome sequencing, they can easily find help on the internet, and they can check for existing sequencing data in the data base. Another is the gene editing, such as CRISPR Cas9 technology. The combination of those two things leads to quick development of genetic research. If we can affirm the connection between gene mutation and FTD and ALS, it’s not impossible for us to modify related genes.

Reference：

The C9orf72 repeat expansion disrupts nucleocytoplasmic transport