Olivia Olson
Dr. Alex Hill
Bio A 348
9 December 2016
Tay-Sachs: Why so Selective?
There are aspects of nature that puzzle the world. Scientists, as curious as they are, try to figure out and solve nature’s great mysteries. One biological phenomenon that appears is Tay-Sachs disease. This is a disorder that tends to appear in only a handful of populations around the world. For quite sometime it was a mystery as to why this deadly disease tended to only show up in certain populations; but thanks to advancements in medical technology not only have scientists been able to understand the biology behind Tay-Sachs but plausible theories have been uncovered as to why Tay-Sachs has a tendency to occur more frequently only in 3 particular populations. …show more content…
There is a gene called the HEXA gene that “provides instructions for making part of an enzyme called beta-hexosaminidase A” which is an integral part in the proper function of the brain and spinal cord (“Tay-Sachs Disease” 1). This enzyme lies within the lysosome, which “are structures in cells that break down toxic substances and act as recycling centers” and within the lysosome, the HEXA gene helps break down a “fatty substance called GM2 ganglioside” (“Tay-Sachs Disease” 1). Tay-Sachs then occurs when there is a mutation within the HEXA gene, which disturbs the process of the gene; when this happens the GM2 ganglioside rises to toxic levels especially in the neurons in the spinal cord and brain (“Tay-Sachs Disease” 2). This then causes all of the neurological and motor function issues that arise within someone who is afflicted by …show more content…
Tay-Sachs is a biological phenomenon, which tends to only occur in certain populations. Three of the most common populations in which it occurs are Ashkenazi Jews, French Canadians, and Louisiana Cajuns. Tay-Sachs is an autosomal recessive pattern that is inherited through both sides of the parents (“Tay-Sachs Disease” 5). An autosomal recessive pattern occurs when “both copies of the gene in each cell have mutations (“Tay-Sachs Disease” 3). While each parent much carry one copy of the mutated gene, they characteristically do not show any signs of Tay-Sachs (“Tay-Sachs Disease” 2). By far, the highest rate of Tay-Sachs is among the Ashkenazi Jews; however this prevalence rate has decreased dramatically due to advancements in medical technology including widespread carrier screening (Fernandes et al. 1466). In the United States, approximately one in every 27 Jews is a “carrier of the Tay-Sachs disease gene” (“Learning About Tay-Sachs Disease” 2). A belief that is held behind why Tay-Sachs seems to be so prevalent and not in many other populations is the high rate of endogamy within the population. Endogamy is the practice of marriage between individuals within a certain population and not marrying outside of it. There is only an estimated 0.5% rate of admixture “per generation over the 80 generations since the founding of the Ashkenazi Jews” (Ostrer 892). Because of this extremely low amount of admixture, this data indicates that this population of people
Dr. Alex Hill
Bio A 348
9 December 2016
Tay-Sachs: Why so Selective?
There are aspects of nature that puzzle the world. Scientists, as curious as they are, try to figure out and solve nature’s great mysteries. One biological phenomenon that appears is Tay-Sachs disease. This is a disorder that tends to appear in only a handful of populations around the world. For quite sometime it was a mystery as to why this deadly disease tended to only show up in certain populations; but thanks to advancements in medical technology not only have scientists been able to understand the biology behind Tay-Sachs but plausible theories have been uncovered as to why Tay-Sachs has a tendency to occur more frequently only in 3 particular populations. …show more content…
There is a gene called the HEXA gene that “provides instructions for making part of an enzyme called beta-hexosaminidase A” which is an integral part in the proper function of the brain and spinal cord (“Tay-Sachs Disease” 1). This enzyme lies within the lysosome, which “are structures in cells that break down toxic substances and act as recycling centers” and within the lysosome, the HEXA gene helps break down a “fatty substance called GM2 ganglioside” (“Tay-Sachs Disease” 1). Tay-Sachs then occurs when there is a mutation within the HEXA gene, which disturbs the process of the gene; when this happens the GM2 ganglioside rises to toxic levels especially in the neurons in the spinal cord and brain (“Tay-Sachs Disease” 2). This then causes all of the neurological and motor function issues that arise within someone who is afflicted by …show more content…
Tay-Sachs is a biological phenomenon, which tends to only occur in certain populations. Three of the most common populations in which it occurs are Ashkenazi Jews, French Canadians, and Louisiana Cajuns. Tay-Sachs is an autosomal recessive pattern that is inherited through both sides of the parents (“Tay-Sachs Disease” 5). An autosomal recessive pattern occurs when “both copies of the gene in each cell have mutations (“Tay-Sachs Disease” 3). While each parent much carry one copy of the mutated gene, they characteristically do not show any signs of Tay-Sachs (“Tay-Sachs Disease” 2). By far, the highest rate of Tay-Sachs is among the Ashkenazi Jews; however this prevalence rate has decreased dramatically due to advancements in medical technology including widespread carrier screening (Fernandes et al. 1466). In the United States, approximately one in every 27 Jews is a “carrier of the Tay-Sachs disease gene” (“Learning About Tay-Sachs Disease” 2). A belief that is held behind why Tay-Sachs seems to be so prevalent and not in many other populations is the high rate of endogamy within the population. Endogamy is the practice of marriage between individuals within a certain population and not marrying outside of it. There is only an estimated 0.5% rate of admixture “per generation over the 80 generations since the founding of the Ashkenazi Jews” (Ostrer 892). Because of this extremely low amount of admixture, this data indicates that this population of people