Editing the Genetic Code INSIDE the Body??

On Monday, scientists attempted to edit a gene within the human body for the very first time in history, in order to permanently change a person's DNA  to cure a disease. Brian Madeux, 44, suffers from Hunter Syndrome. The syndrome is a rare genetic disease (less than 10,000 people worldwide) causing a missing or malfunctioning gene that prevents the body from breaking down mucopolysaccharides. The buildup of these complex molecules can lead to a number of symptoms: frequent colds and ear infections, distrorted facial features, hearing loss, heart problems, breathing trouble, skin and eye problems, bone and joint flaws, bowel issues, and developmental delays. Madeux currently needs regular enzyme replacement therapy to break down the mucopolysaccharides, but while the weekly doses help to ease some of the symptoms, it is time-consuming, costly ($100,000 to $400,000 a year), and doesn't prevent brain damage.

The experimental treatment given to Madeux included infusing billions of copies of a corrective gene as well as a genetic tool to cut his DNA in a precise spot into his bloodstream through an IV. The gene editing tool used is called Zinc Finger Nuclease, which involves a virus that has been reprogrammed to find and attach to specific cells, inserting the new gene and two zinc finger proteins. The therapy has been designed so that it becomes active only once it has reached the appropriate destination, which in this case is the liver cells. The hope is that this will fix the kinks in Madeux's genetic code, helping to relieve him of many of the symptoms associated with Hunter Syndrome and prevent him from requiring the necessary weekly enzyme therapy.

Gene editing has been used before, but cells were always removed from the body, edited, checked for errors, and then injected back into the patient. This approach works in many cases where tissue can be temporarily removed and later returned, but it is impossible for organs such as the liver, heart, or brain.

The first results from Madeux's treatment are expected within a month, but the researchers will know for certain if the treatment worked within three months' time. The treatment will not be able to reverse all of the damage in his body, but it is expected to halt the progression of the disease. If this treatment proves successful, it could potentially revolutionize modern medicine, helping to ease the discomforts associated with many different genetic diseases.



Sources:
http://www.iflscience.com/health-and-medicine/scientists-try-in-body-gene-editing-for-the-first-time/
https://www.outerplaces.com/science/item/17091-genes-edit-inside-body
https://apnews.com/4ae98919b52e43d8a8960e0e260feb0a
http://www.bbc.com/news/health-42009929
http://www.theatlantic.com/science/archive/2017/11/sangamo-first-gene-editing-in-body/545960

Next-generation Sequencing in Forensic Science

The Sanger sequencing method was introduced in the 1970's, which led to enormous advances in molecular biology and genetics. However, the method did have several disadvantages, including low throughput, high cost, and operation difficulties. The introduction of next-generation sequencing (NGS) technology has seemingly overcome these issues, and researchers are now working to further develop the technology to apply to various fields. including forensic science.

DNA analysis is an incredibly important tool in forensic science, where in forensic DNA tests today employ PCR and capillary electrophoresis (CE)-based fragment analysis to detect length variations in short tandem repeat (STR) markers. CE-based analysis, though, comes with several limitations, including the inability to analyze multiple genetic polymorphisms in a single reaction using a single workflow, low resolution mtDNA and mixture analysis, and low-resolution genotyping of current markers. NGS technology allows for the ability to sequence millions to billions of DNA molecules in parallel, increasing the throughput and minimizing the need for the fragment-cloning method used in Sanger sequencing. It includes second- and third-generation sequencing technology, which can analyze a large number of samples simultaneously and determine the base composition of single DNA molecules, respectively. The limitations presented by CE-based analysis are therefore pushing researchers to further explore the potential for NGS technology in forensic science.

DNA sequencing is also an important tool in forensic identification, and a number of recent studies have found evidence supporting the idea that epigenetic markers could be used to distinguish monozygotic (MZ) twins, predict tissue type, and accurately determine the age of a DNA donor. It is thought that information within the human genome could provide insight into a person's characteristics such as ethnicity, physical and psychological characteristics, and age. It is a real possibility for next-generation sequencing to be used in the future to infer a criminal suspect's physical, psychological, and geographical characteristics from biological samples collected from crime scenes.

Although NGS seems to have a future in forensic science, it still has a long way to go and several obstacles to overcome, including the generation of guidelines for its application in the field, before we will see it put to use.


Source:
http://www.sciencedirect.com/science/article/pii/S1672022914001053