Differing DNA Ancestry in Siblings

     You are taught throughout your life that "blood is thicker than water". Meaning that no matter what, your family will always be there. Because you are closer to them than anyone else in life. However, this may not actually be the case. According to recent studies, biological siblings may actually have less in common with one another than they might think. In one study two siblings, Kat and Evan Abraham, used a genetic ancestry test to determine their ethnic background. While expecting the results to be similar, they received the opposite in some cases. Kat was found to be 13% genetically related to Italy and Greece. While her brother Eddy was 23%. In another similar study, six  complete strangers had roughly the same genetic ancestry according to National Geographic's Geno 2.0 DNA kit.

     Biological siblings can have differing genetic ancestry based on a variety of reasons. DNA shuffle is the slight variations inside of an egg and sperm's DNA. This variation comes from the genetic recombination of DNA. After this shuffling of genetic material, the resulting sperm and egg have their own specific combination of genes. Meaning that each offspring will inherit slightly different DNA from each parent. One can take DNA testing with a grain of salt. As these genetic ancestry tests only compare the incoming DNA material with the samples in the database. And the majority of the samples come from North America and parts of Europe. Resulting in the data from other places to be less specific.

     I myself have a younger brother. This information makes me wonder how similar our genetic ancestry is. All my life i have believed we are incredibly similar. This newfound knowledge on genetic ancestry makes me question myself and the person I call my brother.

Article Link: https://news.nationalgeographic.com/2018/03/dna-ancestry-test-siblings-different-results-genetics-science/
Six Strangers Link: https://www.nationalgeographic.com/magazine/2018/04/race-genetics-geno-dna-ancestry/
Info on National Geographic's Geno 2.0 Kit: https://shop.nationalgeographic.com/collections/u-s-delivery

Diversity of Autism Seen with Siblings

Autism is considered to be a complex disorder in brain development. Those who have autism usually experience difficulties with social interactions. Autism can even effect motor skills and health related thing such as gastrointestinal disturbances. The brain of a person diagnosed with autism acts differently than the brain of someone who does not have autism. Autism can causes its limitations but also it is known that a person suffering from autism may excel in skills such as math, or art to a higher level than someone without autism. It is a widely studied disorder that is still revealing new information on the effects of autism.

Two brothers both have autism yet behave differently.

Recently, genetic testing has been preformed on families that have more than one child with autism. It was found that siblings with autism

do not share the same genetic risk factors and are as distinct in their behavior as any brothers and sisters.

In this study 85 families who have two children diagnosed with autism were tested. By using whole genome sequencing technology the children's genome was mapped to identify every inch of their DNA to determine the relationship between the DNA of both children. It was found that only about 30 percent of the siblings shared the same genetic mutations while the remaining 70 percent did not. This is quite shocking because even in very closely related individuals the cause of autism and how the autism affects their behaviors are different. Those who shared the genetic mutations with their sibling showed similar behavior in their habits or skills compared to those that didn't have the same mutation. This study shows how diverse autism can be and why it is so difficult to understand. The study shows potential but needs to be expanded to more families to obtain a more accurate understanding of what it means to share or not share the genetic mutations. Hopefully in the future this kind of genetic mapping will help doctors determine a families risk of conceiving another child with the same disorder. Autism has a "mind of its own" so to speak, it causes different people to behave differently and with more genetic research the hope is to determine how the disorder does this and if anything can be done about it.

Autism Isn’t As Similar As We Think

In the article, “More Differences Than Similarities Are Found in Autistic Siblings”, that was in New York Times the topic was about autism and genetics. The original thought was that siblings with autism would have autism that is similar to each other, which they realized was not true. The study was done with 85 families, using their whole-genome sequence, which they mainly focuses on around 100 genetic glitches that were associated with autism. The data that surprised the researchers was that only about 30 percent of the siblings shared the same mutation. The way hospitals analyze the genetics is not affective and they are hoping that this data can change that. The example they showed was that when a family had one autistic child and one with no developmental problems and the doctors were assessing the chances of having another autistic child, although not a great chance, the family did have another autistic child and they expected both of their autistic children to be alike. That was where they were wrong, the two autistic children were opposites, one was friendly, loved electronics, and always on the move and the other was shy, not into electronics, and like to stay in one place. The study was effective; the outcome was just shocking to the researchers. The 30:70 ratio may have been skewed, but they still believe that it is still true that more are different than alike, the way all siblings are.

Since it is National Autism Awareness Month, I found this article appropriate. Although I do not have anyone in my family that is affected by autism, I have gone to a local special services school to volunteer and worked with children with disabilities, many of which had autism, and I loved working with them and they did have siblings there and they were completely different. So it was cool to see that they article made a point that many autistic siblings are not always similar to each other, just as other siblings are not even though autistic siblings have a mutation. The more we understand autism, the easier it may be on families, so the more research done, the better.

The Genes Responsible for Autism May be Different in Siblings

              With the recent outbreak of measles around the country. There has been a lot of controversy over the use of vaccines and the link to autism. Autism is a spectrum disorder that is characterized by the impairment neuro-development, social interactions, and communication. In a study conducted by Dr. Stephen Scherer of The Hospital for Sick Children in Ontario, a question about the inheritance of autism was posed. Dr. Scherer sequenced the genome of 85 families in which two siblings had autism. The results of the study showed that in 69.4% of the sibling, the autism related, genetic mutations were different. These sibling also displayed more variability in their symptoms than 30.6% of the siblings who had the same autism risk gene.  Research conducted by the CDC shows that in a pair of identical twins, if one sibling as autism, the other twin has a 36-95% chance of developing the condition. Although these findings were surprising, Dr. Scherer realized that more than 100 genes are involved in the prognosis of autism, because of this it makes sense that different genes are involved rather than the same genes.

            Many time when parents have one child with autism and are expecting a second child, they will modify the autism gene that is identified in the older child, through gene therapy in the younger child. Dr. Scherer's study shows that, although one gene may influence the older child, it may not necessarily be the same gene that is affecting the younger child. I found this article to be interesting, because New Jersey has one the highest rates of autism in the country. I never realized that autism could in fact be hereditary, and that parents of an autistic child, have a higher rate of having another child with autism. This study can be used to help parents intervene early in the diagnosis of their child and understand that although they may have several autistic children, the disorder may not have the same origin.

Article: http://www.medicalnewstoday.com/articles/288574.php

Secondary Article: http://www.ninds.nih.gov/disorders/autism/detail_autism.htm