Genetic Factors that Cause Female Infertility

Many women are unable to deliver healthy babies due to genetic factors. Occasionally, this is caused by an inherited chromosome abnormality. It may also be caused by a single-gene defect that is passed from parent to child. Also, if some women in your family have had difficulties conceiving due to endometriosis, premature menopause or other factors, you may experience the same problems.
Chromosomally abnormal embryos normally have a low rate of implantation in the womb of the mother, leading to miscarriages. If implantation of an abnormal embryo occurs, there may be still a miscarriage, or a baby is born with development delays, physical problems, or mental retardation.
There are five main kinds of chromosome abnormalities: translocation, aneuploidy, mutation, inversion, and deletion. Translocation is one of the most common kinds of chromosome abnormalities. Although parents with translocation are frequently normal, their embryos may receive too little or too much genetic material, resulting in a miscarriage.
Changes in the DNA sequence of a gene causes mutations that are known as single-gene abnormalities. Usually, single-gene disorders show the history of specific genetic disorders such as cystic fibrosis (an incurable disease that affect the mucous glands of vital organs) and Tay Sachs (a fatal condition that causes harmful quantities of a fatty substance to build up in nerve cells and tissues in the brain). Although they are rare, these diseases are typically devastating to a family.
References
https://fertilitynj.com/infertility/female-infertility/genetic-causes/
http://accessmedicine.mhmedical.com/content.aspx?bookid=1094&sectionid=61904709

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Genetics Might Be the Reason Why You Don’t Want to Exercise

If you don’t like exercising, it is possible you’re not lazy. A new study from the Vrije Universiteit Amsterdam in the Netherlands says the reason some people dislike exercising is genetic.
The study enlisted six sibling pairs, not from families with twins, 35 siblings related to the twins, 111 pairs of non-identical twins and 115 pairs of identical twins. Everyone rode an exercise bike for about 20 minutes, both at a comfortable pace. The researcher’s monitored breathing, ensuring the workouts were low intensity. The routines were accompanied by a warm up and cool down. Participants also completed a short, vigorous ride on the bike.
While exercising, the siblings were asked how much effort they put in while exercising, how they felt, and whether they were lively, tense, energetic or jittery. Also, the subjects were asked how often they exercised. Using the responses, scientists determined the psychological state of the participants during the physical activity.
The researchers concluded that genetics could account for up to about 37% of the differences in the way we experience exercise. While this new study shows that some people are born to love exercising, there is no denying that people should still do it.
References
http://www.kix.fm/2016/11/10/new-study-says-the-reason-you-dont-like-exercise-is-genetic/
http://www.medicaldaily.com/genetics-not-laziness-might-be-why-you-hate-exercising-421561
https://www.cbsnews.com/news/love-or-hate-exercise-it-may-be-in-your-genes/

How Dogs Evolved into the Adorable Pooches We Love Today

In an attempt to explain how dogs evolved into adorable pooches we love, researchers have identified some genetic mutations that may have influenced their personalities. The study is part of a broader push to know mysterious origins of the dog, and explain how they became our best friends.
Dogs have evolved to enjoy being around people. In return for their affection, they have convinced us to take of them. In the prehistoric time, it is believed that wolves began trailing human hunter and gathers to scavenge their kills. Frightening wolves were killed while friendlier wolves were fed extra scraps— and over time, friendlier wolves in due course evolved into dogs.
Monique Udell and Bridgett vonHoldt, evolutionary geneticists at Oregon State University and Princeton University respectively, led a team of researchers to find out the difference between wolves and dogs. Using a combination of behavioral tests and genetic sequencing, they identified a few genetic differences that appear to track with friendliness. According to Adam Boyko, a dog geneticist at Cornell University, the study may be one of the studies ever to pinpoint specific gene variants that played a big role in turning wolves into dogs.
The researchers started by testing how ten wolves and 18 dogs behave around people. The wolves and dogs were tasked with getting a summer sausage from a box either alone or in front of a person. In all trials, the wolves fought the dogs and stayed focused even in the presence of a human. However, the dogs could not; they spent more time gazing affectionately at the person than at the sausage.
In an earlier study, Bridgett vonHoldt pinpointed a gene that mutated more often in dogs compared to wolves— perhaps because of domestication. The gene also resembles one in human that is among several deleted in individuals born with a condition known as WBS (Williams-Beuren syndrome). People with WBS are friendly and social, which made the scientists suspect that these genes are important for friendliness in both human and dogs.
References
https://www.theverge.com/2017/7/19/16000172/dogs-wolves-canines-genetics-evolution-domestication-love-best-friends
http://www.npr.org/2011/11/08/142100653/how-dogs-evolved-into-our-best-friends

The Role of Genetic Counselors in Society

Genetic counselors, as members of healthcare team, provide information and support to people at risk of or affected by genetic diseases. They act as a source of information about genetic diseases for patients, healthcare professionals, and the general public.
To identify families at risk of genetic disorder, genetic counselors gather and analyze family history, patterns of inheritance and calculate chances of reappearance. They offer information about genetic testing and associated procedures. Genetic counselors are trained to present difficult-to-comprehend and complex information about genetic testing, risks, and diagnosis to patients and families. They help people to understand the significance of genetic diseases about personal, cultural, and familial contexts.
Genetic counseling sessions include a pre-testing and post-testing session. In the initial genetic counseling, the genetic counselor determines why the patient is seeking genetic counseling. They collect and record a medical history of the patient’s family, and assess the psychological and medical history of the patient. If the patient asks for a genetic testing, the genetic counselor is often the person who communicates the results.
In general, the role of genetic counselors is to increase the people’s understanding of genetic disorders, help family and individual identify the psychosocial tools needed to face potential outcomes and to reduce the family’s anxiety.
References
https://www.ncbi.nlm.nih.gov/books/NBK115552/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4666564/

Tongues ‘taste’ water by sensing sour

All we know about water is that water is an odorless, tasteless, slightly compressible liquid when it’s pure. However, when we drink water, we can know that it’s water. It might be unsurprising to notice that we’re drinking something liquid. But how do we know that it’s water, not syrup? Then, does it mean that water has a taste? – actually not. According to the new study, we can recognize the water not by tasting the water itself, but by sensing acid which is produced when we drink water.

All mammals need water to sustain their life. When we drink water, we have to drink the water through our mouth.According to Yuki Oka who studies the brain at the California Institute of Technology in Pasadena, our tongue has evolved to detect some necessary materials for survival like salt and sugar. This, in other words, means that the sense of detecting water would have evolved.

It is already found that a brain area called the hypothalamus controls thirstiness of mammals. But a brain cannot decide the taste of something alone because, in order to taste something, the brain should cooperate with a mouth and receive a signal from it to know what the person’s eating or drinking. Oka says, “There has to be a sensor that senses water, so we choose the right fluid.” If we cannot distinguish the water from others, we might make a fatal decision, such as drinking poison instead of water.

To prove the water sensor, Oka and his group used mice. They dripped different flavors of liquid onto mice’s tongues. They observed a signal from the nerve cells attached to the taste buds when they were drinking, and mice showed a great nerve response to all tastes. However, the main point is that they reacted to water similarly. Somehow, the scientists discovered that taste buds are able to detect water.

Our mouth is filled with a lot of saliva— a mixture of enzymes and other molecules. Also, the mouth includes bicarbonate ions (HCO3-), which make saliva more basic. The pure water has lower pH than basic saliva. When we pour the water into the mouth, it washes out the basic saliva and enzymes in our mouth instantly starts to replace the ions. It combines carbon dioxide and water to produce bicarbonate. As a side effect, it also produces protons. The bicarbonate is basic, but the protons are acid. Then, the receptors on our tongue detect acid that we usually call ‘sour flavor’ and sends a signal to the brain.

To confirm this, Oka and his group used a technique called optogenetics. In this method, scientists insert light-sensitive molecules, which trigger an electrical impulse when shone with light, inside cells. With this principle, Oka’s team added a light-sensitive molecule to the sour-sensing taste bud cells of mice. As they shone the light to their tongues, they started to lick the light as if they lick the water. By stimulating acid sensor, they misunderstood it as water.

To the other group of mice, Oka’s team removed the sour-sensing molecule by blocking the genetic instructions that make this molecule. As a result, they weren’t able to know whether what they’re drinking is water or not. They even drank thin oil instead. Oka and his group published their results on May 29 in the journal Nature Neuroscience.

Scott Sternson, who studies brain’s mechanism for controlling animal behavior at a Howard Hughes Medical Institute research center in Ashburn, VA, says it’s crucial to learn how we sense simple but vital things, such as water. “It’s important for the basic understanding of how our bodies work,” he says.

Some people might think it’s a weird concept that the water has a sour ‘taste’. Flavor is a complex interaction between taste and smell. So, detecting water is quite different with tasting. Water may still taste like nothing, but to our tongues, it’s definitely something.

Reference: https://www.sciencenewsforstudents.org/article/tongues-taste-water-sensing-sour

 

Genetic Testing Before and During Pregnancy

Genetic testing before and during pregnancy is given to expecting or prospective parents to look for unusual genes that can cause certain diseases in their baby. Many genetic diseases are referred to as recessive disorders,” meaning that each parent must pass along an abnormal gene to the child for the child to get the disorder. In other words, if one parent screen positive for a genetic disorder but his/her partner does not, the child will not inherit the disorder. And even if both parents screen positive, there is only 25% chance the child will have the condition.
Ideally, genetic testing is done before parents start trying to get pregnant. However, because many pregnancies are accidental, many couples go for genetic testing early in pregnancy.
Getting screened before you get pregnant can help you make an informed decision or reassure you. If it turns out that couples are carriers of a certain genetic disease, they can start preparing to live with a child that has a genetic disease, choose to learn about various prenatal tests to check if their baby is healthy, or they can consider other options such as sperm or egg donation or adoption.
Once you get pregnant, getting tested can help you decide the right prenatal tests for the baby, and what to look for if you decide to have them. For instance, if you know your baby is at increased risk for having sickle cell disease or cystic fibrosis, your physician can look for those disorders specifically through either amniocentesis or a CVS(chorionic villi sampling)
References
http://www.parents.com/getting-pregnant/genetics/tests/genetic-testing/
http://kidshealth.org/en/parents/genetics.html