Category Archives: genetics

Why do people undergo cosmetic surgery?

Why do people undergo cosmetic surgery? It’s a simple question that’s unlikely to yield a simple answer.

Cosmetic surgery’s original intention was to treat the patients who have injured their physical appearances such as physiognomy. However, including Korea, lots of countries’ denizens are undergoing cosmetic surgery in order to achieve “beauty”.


A common comment from those who have gone under the knife or needle is “I do it for myself.” But what does that really mean? Maybe that the patient decided on surgery because of the benefits it confers on the self, not for any effects it might have on others, such as romantic partners or rivals. “I do it for myself” also emphasizes the free will of the patient: he or she doesn’t feel pressured into surgery by outside forces, such as peer pressure, the media, or advertisements.

However, new research published recently has questioned the motives of those who opt for cosmetic procedures and suggests that they may be more complex than many would care to admit.

 

One of the clearest benefits of cosmetic surgery is that it improves appearance. If it didn’t, nobody would spend the money or go through the pain associated with those procedures.

Most of us would rather be more attractive than our peers because attractiveness confers all kinds of benefits, including the ability to compete for higher-value partners.

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Syrian boy who had epidermolysis bullosa is transplanted transgenic cell

Epidermolysis bullosa is a genetic disease that causes blisters and chronic wounds.  Epidermolysis bullosa occurs when the epidermal layer of the skin cannot attach fitly to the underlying dermis by the mutated connective protein. Epidermolysis bullosa is known as an incurable disease. Treatment only cares for blisters and prevent a new one. However, there is a good news. A few days ago, a team announced that a seven-year-old Syrian boy who transplanted transgenic replacement because of epidermolysis bullosa showed some progress.  In 2015, regenerative medicine specialist Michele De Luca met doctors in Germany whose Syrian patient was suffering by epidermolysis bullosa. Laminin b3, a protein that regulates the attaching epidermal cells, was not encoded properly in the patient’s gene. Although Syrian boy met a doctor in Germany, his condition became more severe. He even lost approximately 80 percent of his epidermis. De Luca had experience in transgenic cell therapy. His patients were lack of small patches of the epidermis. On the other hand, the boy needed approximately 80 percent of replacement. However, his condition was the worst and his parents decided to treat their son using transgenic cell therapy. From his biopsy, keratinocyte, a bountiful cell type in the epidermis, was extracted and transducted so that the gene in the boy’s cell encodes the laminin b3. After the cells grow enough to cover his epidermis, they were grafted in two operations.  After the operations, his new skin attached properly to the underlying dermis and had appropriate levels of laminin b3. Now, his skin does not show any defects. According to Michele De Luca, “he’s back to school, he’s exercising, he’s started to play soccer… it’s quite amazing.”

Other scientists showed a positive response.  

“It establishes a landmark in the field of stem cell therapy,” Elaine Fuchs, a skin scientist at the Rockefeller University.

“The work provides in-depth, novel information on skin stem cells and demonstrated the great potential of these cells for treating a devastating disorder,” says Allessandro Aiuti, a professor at the San Raffaele Scientific Institute

 

 

https://www.mayoclinic.org/diseases-conditions/epidermolysis-bullosa/symptoms-causes/syc-20361062

http://www.the-scientist.com/?articles.view/articleNo/50911/title/Child-Receives-Transgenic-Skin-Over-Most-of-His-Body/

https://www.lonza.com/products-services/bio-research/primary-cells/human-cells-and-media/keratinocytes-and-media.aspx

 

Clone Editing by using CRISPR

Fascinating, marvelous, and astonishing would be the appropriate words to describe people’s reactions when they see this provocative topic. Nowadays, scientists can edit the clone by using the method called CRISPR, and Chinese scientists have proved that it is plausible. The intention was to fix genetically malfunctioning genes in human embryos in order to prevent future disorders caused by those genes. The researchers created cloned embryos with a genetic mutation that could cause fatal blood disorder. In addition to that, they were able to precisely correct the DNA by changing the sequence of genes into the normal type.

CRISPR is an abbreviation of Clustered Regularly Interspaced Short Palindromic Repeats,  and this method was used by the scientists to modify the gene sequences. Huang’s team used ‘based editing’, a modification of CRISPR-Cas9. By using this method, they were able to introduce an enzyme to specific gene sequences but does not cut the DNA. Instead, the Cas9 enzyme was disabled and tethered to another enzyme that can swap out individual DNA base pairs. It is a common knowledge that hundreds of genetic diseases are caused by single-based changes, or ‘point mutations’; however, thanks to the CRISPR, scientists were able to edit the point mutations during the embryonic stage and could potentially stave off such conditions. Apparently, Huang and his co-workers were able to convert the genes from 8 embryos out of 20, which is the pretty low rate to be considered for clinical use, but still, the efficiency was high relative to that achieved in other gene-editing studies.

Apparently, Huang and his co-workers were able to convert the genes of 8 embryos out of 20, which is a pretty low rate of success to be considered for clinical use, but still, the efficiency was high compared to that achieved in other gene-editing studies. Some scientists argue that this method could cause off-target effects-unintended genetic changes during the conversion. However, the authors reported that none of these problems were found during the experiment. In the future, in order for this method to be used practically, the scientists would need to improve the rate of successful conversion of certain genes.

http://www.nature.com/news/chinese-scientists-fix-genetic-disorder-in-cloned-human-embryos-1.22694

https://en.wikipedia.org/wiki/CRISPR

http://www.twis.org/2017/10/06/2209/

What is CRISPR Cas9?

Have you ever heard about hemophilia? It is a rare genetic disease that disables people from clotting blood. There is not yet therapy for hemophilia. However, a new technology to change the genes related to hemophilia was developed recently. The key point in this new technology is CRISPR-Cas9. It is genetic engineering tool which enables people to cut specific region of DNA and to insert another homologous DNA. Cas9 and guide RNA (gRNA) are important molecules in CRISPR-Cas9.

Cas9, a restriction enzyme, was first discovered in the 1980s. When a virus infects a bacteria, the bacteria cut the intruder’s DNA by using Cas9.

gRNA is made from a small piece of pre-designed RNA sequence. gRNA helps the Cas9 enzyme to cut particular regions of DNA.

CRISPR stands for Clustered Regularly Interspersed Short Palindromic Repeats. Also, Cas means “CRISPR associated.” Even though this method does not destroy surrounding genes, it is possible to change a particular DNA sequence. Treatments for hemophilia using CRISPR-Cas9 are being studied now in the USA. Researchers say, “If a ‘normal blood clotting factor’ gene is inserted into a hemophilia patient, his or her blood will be clotted.”

In addition to hemophilia, CRISPR therapy related to HIV is also being studied. HIV, or Human Immunodeficiency Virus, is a virus that infects the body immune cells and corrupts the immune system.  One typical thing of HIV is that it can go into the immune cell using the specific receptor proteins that are on the surface of the immune cells. Using CRISPR method, scientists found out that getting rid of these proteins makes HIV unable to infect another cell. Then, without the proteins that enables them to infect other cells, HIVs cannot replicate themselves and therefore collapse.

Also, CRISPR is applied to not only curing genetic diseases but also developing plants and animals. By using CRISPR, researchers made MSTN, which limits the growth of pigs, not perform its role. As a result, researchers were able to get a “super pig,” that has more muscles than normal pigs.

The usage of CRISPR can make valuable crops. In 2016, Dr. Yang and his companions made new mushrooms that doesn’t turn into brown by eliminating the enzymes that cause browning in mushrooms. Korean researchers also developed various crops, such as lettuce that has resistance in harmful insects and bean that decreases the level of cholesterol.

Although CRISPR Cas9 is touted through many positive results, it is a controversial topic. For example, CRISPR Cas9 can be used in manipulating embryonic genes, which causes the whole fetus to change. Some countries prohibit this for ethical reasons. In contrast, the Human Fertilisation and Embryology Authority authorized to alter human embryos in the UK in 2016. Even though there are lots of positive effect modifying genes, we must know that there are some ethical issues that we must concern.

References

http://www.alphr.com/bioscience/1001654/darpa-offers-50-million-to-make-crispr-gene-editing-safer
http://news.mk.co.kr/newsRead.php?year=2017&no=461478

http://science.ytn.co.kr/program/program_view.php?s_mcd=0082&s_hcd=0010&key=201706011107334239

https://www.youtube.com/watch?v=2pp17E4E-O8

http://www.yourgenome.org/facts/what-is-crispr-cas9

Understanding Genetic Variation

geneticvariation-02

Genetic variation is a term that is used to describe the DNA sequence variation in human genomes. It is what makes all people unique, whether in terms of skin color, the shape of our faces, or hair color. Although individuals of same species have similar characteristics, they are rarely identical. That difference in those individuals is referred to as variation.

Amongst people, single nucleotide polymorphisms are the most common type of genetic variation. Each nucleotide polymorphism denotes a difference in a base of single DNA. In a person’s DNA, DNA bases are A, C, G or T.

Genetic variation is a result of different alleles of genes. For instance, looking at eye color, individuals with blue eyes have a unique allele of the gene for eye color, while individuals with brown eyes have a different allele of the gene.

Face shape, height, skin tone and eye color are all determined by our genes. Therefore, any variation that occurs is due to the genes we inherit from our parents. In contrast, while weight is partly influenced by genes, it is highly influenced by environment. For example, how often we exercise and how much we eat.

References
http://www.yourgenome.org/facts/what-is-genetic-variation
https://www.nature.com/scitable/topicpage/the-genetic-variation-in-a-population-is-6526354

 

 

Understanding Penetrance in Genetics

 

In genetics, Penetrance is the percentage of people carrying a specific variant of a gene that also shows an associated trait. Penetrance of a disease-causing mutation is the percentage of people with the mutation who display clinical symptoms. For instance, if a mutation in the gene that results in a specific autosomal dominant disorder has 80 percent penetrance, then 80 percent of those with the mutation will have the disease, while 20 percent will not.
If clinical symptoms are shown in all people who have the disease-causing mutation, this condition is said to have complete penetrance. A condition that shows complete penetrance is referred to as neurofibromatosis type 1. In this case, the penetrance is 100 percent.
An allele is said to have incomplete penetrance if some people who have the disease-causing mutation do not express the characteristic even though they are carrying the allele. An autosomal dominant condition that shows incomplete penetrance, for example, is familial breast cancer.
If an allele has low penetrance, the trait that it expresses will not be obvious in an individual that carry the allele. An allele with high penetrance results in a trait that is almost always apparent. In low penetrance cases, it can be difficult to differentiate genetic from environmental factors.
References
https://www.nature.com/scitable/definition/penetrance-69
http://genegeek.ca/2012/10/penetrance-vs-expressivity-why-the-confusion/

Fatigue is Partly Influenced by Genes

Genes may contribute to why some people suffer from low energy levels or tire easily. According to recent research, being prone to fatigue is partly heritable, with genetic accounting for 8% of differences between individuals who were asked about their tiredness levels.
The study was led by Saskia Hagenaars and Dr. Vincent Deary, from the University of Edinburgh and Northumbria University respectively. They examine genetic make-up of 111,749 people who had reported whether they had low energy or felt tired in the two weeks before collection of data.
Also, the researcher also discovered that genetic predisposition to fatigue was also present in individuals genetically susceptible to various physical and mental health conditions, such as schizophrenia, depression, and smoking. Additionally, an overlap was identified between low levels of energy, and high levels of cholesterol and obesity.
According to the scientists, this raises the likelihood of a genetic linkage between fatigue and a susceptibility to physiological stress. The researchers also found that there was an overlap between a general tendency to poor health and tiredness.
The researchers said that most of the differences in tiredness are mainly environmental. The genetic data accounted for just 8.4% of people’s differences in tiredness. The findings were published in the journal Molecular Psychiatry.
References
http://www.ed.ac.uk/news/2017/tiredness-is-partly-genetic-study-says
http://scopeblog.stanford.edu/2017/03/06/feeling-fatigued-your-genes-may-be-partially-responsible-new-study-says/