Introduction Human manipulations of genetic transfer are methods to change the base sequence of DNA. Changing the base sequence of DNA can have many applications in the health industry-i.e. controlling the disease Tay-Sachs, which causes neurological deterioration. About Tay-Sachs Tay-Sachs is caused by a mutation in the allele that codes for a very specific enzyme (hexosaminidase-A). The mutations result in a faulty enzyme that cannot carry out its function being produced. The mutated allele for Tay-Sachs is unusually frequent amongst the Ashkenazi Jewish population (1 person in 27 are carriers, compared to 1 person in 250 in the general population). Tay-Sachs is a recessive condition, meaning that offspring must receive a copy of the mutated allele from each parent in order to inherit it. Hexosaminidase-A catalyses the biodegradation of gangliosidoses. Without the enzyme catalysing the biodegradation, the gangliosidoses are only partly metabolised. They accrue in the brain, causing damage to the nervous tissue. “Deterioration of the central nervous system becomes apparent at about six months of age. Symptoms include loss of coordination, blindness, deafness, seizures, and severe mental retardation. The average life expectancy is three to five years.” (http://www.jewishgeneticdiseases.org/diseases/tay-sachs-disease/, 14/08/2014) Tay-Sachs has no current treatment. Selective Breeding A method that humans use to control Tay-Sachs is selective breeding. Selective breeding
Since children lack the HEXA-A gene it causes progressive damage and eventually the nervous system will shut down because it can no longer produce vital neurons needed to function the nervous system and life. Beta-hexosamindinidase is located in the lysosomes, which are structures in cells that act as recycling centers and breaking down the toxic substance. Beta-hexosamidnidase role is toxic and fatty substances called GM2 ganglioside. If the gangliosides become overpowering or too much, can cause destruction of the neurons. The excessive storage of the gangliosides in lysosomes is another factor that causes Tay-Sachs. Tay-Sachs occurs usually when the individual lacks the protein hexosamindinidase A and defected and alterations on chromosome 15 (specifically 15q23-q24). More than 50 mutations having been discovered on chromosome 15 and HEXA-A enzyme. The mutation can vary as in deletion, insertion, and splitting in which each mutation alters the protein. The mutation and disorder cause a decrease in enzymes activity. The severity of the disorder depends on the degree of the enzyme activity and deficiency. For example, one mutation includes, the mutation includes a G-to-T substitution at the 3-inch end of intron 5, which makes a short mRNA. Then skipping exon 6 and the polypeptide lacking 34 amino acids. (Tanaka
The enzyme hexosaminidase is a crucial hydrolytic enzyme found in the lysosomes. When this enzyme no longer functions properly, lipids accumulate in the brain and cause interference with normal mental processes. Simple blood tests can determine presence of Tay-Sachs due to measurement of the levels of activity for hexosaminidase. The hydrolysis, (or breakdown) of the gangliosides requires three proteins: two of which are subunits of the enzyme hexosaminidase A, and the other being a small glycolipid transport protein that acts as a substrate (catalyst) for the enzyme. Deficiency in any of these proteins can lead to abnormal ganglioside storage, primarily in the lysosomes of neurons. Tay-Sachs disease occurs because of a mutation like this, either inhibiting or deactivating this process. The mutation occurs not at the active site, but instead because of incorrect function of intracellular transport. Infants with the disease Tay Sachs usually appear normal and healthy until three to six months of age. At this time, their development usually begins
Tay Sachs Disease, or TSD, is a fatal genetic disorder that result in the degeneration of the nervous system. TSD is presented in three forms, those being classic infantile, juvenile and adult late-onset. The most commonly seen form of TSD is that of classic infantile Tay Sachs Disease. In the classic infantile form, infants generally experience their first symptoms by 6 months of age. Death of infants with TSD is typically by age 5. The symptoms that TSD infants will experience prior to death include: an onset of retardation, paralysis, dementia, blindness and reoccurring seizures. The absence of hexosaminidase-A, or what we will refer to as Hex-A, is the cause
Well what causes Tay Sachs disease is that there’s something wrong with there fifteenth chromosome with this problem your body has trouble making the protein hexosaminidase A, since your body doesn’t make that anymore gangliosides build up and eventually will kill brain cells. In order for your child to get this disease the defective gene has to be passed down from each parent so that would mean that Tay Sachs disease is a heredity disease. If the defective gene just gets passed down from one parent it means that the child is a carrier of Tay sachs disease, in which this means that if this child marries someone who is also a carrier of Tay Sachs disease that means that there child will absolutely have this disease
Tay Sachs Disease is an inherited disease that results in slow destruction of the central nervous system and sensory systems, which is caused by a mutation resulting in a deficiency of a lysosomal enzyme. The missing enzyme, hexosaminidase A, functions in breaking down the fatty material ganglioside GM2, a chemical found in nerve tissue. Without this enzyme, lipids accumulate in the brain cells and destroy them, resulting in damaged nerve cells, neurological problems, and eventually leading to death several years after birth. The disease was first discovered by Waren Tay, a British ophthalmologist in 1881. Tay-Sachs disease is very rare in the general population and is relatively common among certain ethnic groups such as Eastern Europeans
The term ganglioside lipid was thought of because of the high abundance of the brain lipid in normal ganglion cell, a type of brain cell. Other names Tay Sachs disease is known by are B variant GM2 gangliosidosis, GM2 gangliosidosis, type 1, HexA deficiency, Hexosaminidase alpha-subunit deficiency, (variant B), Sphingolipidosis (Genetics Home Reference, 2017). Tay Sachs disease is diagnosed by prenatal tests, such as chorionic villus sampling (CVS) and amniocentesis, can diagnose Tay Sachs disease. Genetic testing is generally done when one or both members of a couple are carriers of the disease. CVS is performed between 10 and 12 weeks of pregnancy and involves taking a sample of cells from the placenta via the vagina or abdomen. Amniocentesis is done between 15 and 20 weeks of pregnancy and involves extracting a sample of the fluid surrounding the fetus using a needle through the mother’s abdomen (Herndon, 2016). If a child is displaying symptoms of Tay Sachs disease, doctors and get a family history, do blood work, tissue sample or do an eye exam to see if the child has a red spot near the
Tay-Sachs follows an autosomal recessive pattern – both copies of the gene possess mutations. Warren Tay first described it in 1881. Bernard Sachs was the first to describe cellular changes and the genetics of it, in 1887. Tay described a patient with a cherry-red spot on their retina. Sachs established the connection the familial connections of the disorder, noting that most babies who had Tay-Sachs were of Eastern European, Jewish descent. If symptoms and physical characteristics suggest that a child may be suffering from Tay-Sachs disease, blood tests are used to determine whether or not the child’s body is producing the necessary Hex-A enzyme. DNA is extracted from the sample in an attempt to detect mutations of the Hex-A. There is no known cure for Tay-Sachs disease. For treatment and to ease the pain of/reduce some of the side effects, doctors may prescribe seizure medications. It is highly recommended that Tay-Sachs patients begin some form of Respiratory therapy. This type of therapy is necessary because children who have Tay-Sachs have a high chance of developing lung
Tay Sachs is a genetic disorder that occurs when there is a missing enzyme in the body. This causes a buildup of fatty substances in the nervous system (Gale). Beta-Hemosaminidase, or HexA, is the missing enzyme that causes the various nerve disorders that happen within Tay Sachs (NTSAD). This disease is inherited in a few different areas of the world, but it is most commonly
The genetic mutations that cause this disease are more commonly found in the Ashkenazi people with a Jewish heritage than those with other backgrounds. French-Canadian communities of Quebec, the Old Order amish community in Pennsylvania, and the Cajun population of Louisiana, are more responsible for the mutation for this disease. The HEXA has been discovered for the cause of Tay Sachs. The gene provides for making part of an enzyme, which is cause, "beta-hexosaminidase A", which plays an important role in the spinal cord and brain. Disruptions in the HEXA gene messes with the activity of beta-hexosaminidase A, and then prevents the enzyme from breaking down GM2 ganglioside. This results the the substance accumulating to toxic levels in the neurons in the brain and spinal cord. Continuous damage caused by the build up of GM2-ganglioside leads to the destruction of the neurons and thus causes the signs and symptoms of Tay-Sachs
Symptoms of Tay Sachs disease is muscle weakness, lacking of muscle coordination, movement issues, problems with speech, and mental issues. The disease is caused by mutations in the HEXA gene. The HEXA gene is responsible for making a part of an enzyme called beta-hexosaminidase A which is located in lysosomes and plays a key role in the brain and spinal cord. The enzyme helps break down a substance called GM2 ganglioside. The mutation will keep the enzyme from breaking down the GM2 and the substance builds up to toxic levels mostly in neurons in the brain and spinal cord. As the GM2 substance builds up even more, the neurons are destroyed and symptoms began to show.
Tay Sachs Disease is an inherited disorder that kills nerve cells in the brain, and also in the spinal cord. A couple of things that could cause this mutation is a missing enzyme. This is an enzyme called ganglioside, that is a fatty substance. Another reason why tay sachs could appear is a change in chromosomes. This is chromosome number 15. The gene is the HEXA gene, or hexosaminidase A. This is a recessive disorder that you can only inherit if both parents have tay sachs. Some symptoms to know if you have this disease is weakened muscles, startling of loud noises, seizures, hearing loss, blindness, and paralysis. If you’re an infant and you have tay sachs disease, you will start to gain abilities, like crawling, but then start to lose them.
In order to review their inherited genetic risks and help them understand and provide counseling according to their specific needs the genetic counselor should know the Trosacks ' have already established that their unborn child has Tay Sachs disease and based on those needs they should be provided with appropriate guidance and counseling as they progress through their pregnancy. The discussion should include what causes genetic disorders, and what that means to the Trosack couple specifically, including dominant, recessive and x-linked disorders. However, recessive disorders should be fully discussed in this case. Another topic to include in the discussion are what genes and chromosomes are, and the relation to Tay Sachs disease.
Author Chuck Klosterman said, “The simple truth is that we’re all already cyborgs more or less. Our mouths are filled with silver. Our nearsighted pupils are repaired with surgical lasers. We jam diabetics full of delicious insulin. Almost 40 percent of Americans now have prosthetic limbs. We see to have no qualms about making post-birth improvements to our feeble selves. Why are we so uncomfortable with pre-birth improvement?” Despite Klosterman’s accurate observation, there are reasons people are wearisome toward pre-birth enhancement. Iniquitous practices such as genetic engineering could lead to a degraded feeling in a child and conceivably end in a dystopian society, almost like the society Adolf Hitler had in mind. In the minds of
What if you could design your child before it was even born? What if you could cut out any life threatening diseases, make sure that your child is not susceptible to smoking addictions or alcoholism, and then make your child genius? Would you? Are you asking yourself how this could be done? Have you ever considered human genetic engineering?
Humans have been manipulating genetic transfer for over 10,000 years since our hunter- gatherer ancestors began to settle in one place and started farming and planting crops. Those humans observed and chose organisms from natural selection to select and breed organisms that showed characteristics desired by them and this began the process of selective breeding. Selective breeding favours recessive alleles that do not persist in wild populations. Selective breeding is a process of increasing the frequency of rare and recessive alleles so that they appear in homozygous form. This has the effect of eliminating the alleles for wild type from the population and the process of domestication has become irreversible. The domestic species has become dependent on humans for their survival. It is from these domestic species that humans have selected and breed favourable genetic traits for their benefit, be it higher yield in plant crops, sweeter tasting fruit, and more milk from dairy cows or ease of handling stock, selective breeding continues to be used today.