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