tay sachs

• Question:-How rare is it for Tay Sachs disease to start to manifest later in life?
  My sister was tested positive for Tay Sachs and my mother decided to carry her to term and but for some reason she never began to show the symptoms of it as a small child like everyone expected. She's 17 now and very bright and seems perfectly normal. The doctors think the symptoms will probably start up eventually though. How rare is late onset Tay Sachs disease and does anyone who has it ever not start to show symptoms at all?
  
  Answer:-She just doesn't have the infantile form of it. The late onset type is nonfatal (great news there!) but often these people have neurodegenerative issues... so she will probably end up not being able to walk on her own. And there are a whole slew of neurological issues that are not great that go along with it (cognitive decline, psychological issues, speech and swallowing issues, etc).
  
  Either way, she really needs to consider getting genetic testing done on her partner if she ever decides to have children. Although it's very uncommon, if her partner is a carrier, they have a 25% chance of having a child with the disorder. She's young, but she needs to think about this NOW.
  
  EDIT - btw, it's VERY rare to get the non-infantile forms of it. The disease is rare to begin with, but her form is even more rare.
• Question:-What should be a bio ethical decision for parents to make if their child has Tay Sachs disease?
  Tay Sachs has no cure and a child could die when they are around 4 or 5. what are some possible decisions for me as a parent to make?
  
  Answer:-http://www.djhomepage.com/
  
  This disease is awful and I am sorry you are and your family are going through this. If the baby is already here you just have to give it the best life possible. If the baby is still a fetus you can terminate. No one can make that decision other than you and your spouse because children with this horrible disease go blind, deaf, can't swallow, eat and are in severe pain. It is an ethical decision because is it right to make a child suffer.
  
  The website listed above is a true story and how I first heard of the disease. I personally have not had any experience with it.
• Question:-What kinds of tests are available to check for Tay-Sachs disease?
  My husband is of eastern european jewish decent... I am not. Do both parents have to be carriers for this to be a concern? Has anyone gone through the testing for Tay-Sachs? What does it involve? Thanks!
  
  Answer:-Hi! I am a Tay Sachs carrier, so I understand what you are dealing with. 1 in 55-60 Ashkanazi (Eastern European Jews) are carriers of Tay Sachs. This is only becomes a problem if both parents are carriers, as both parents need to give the bad gene (you have 1 good copy and one bad copy if you are a carrier) to the child in order for them to have Tay Sachs. People who are white and are not French Canadian, Cajan, or Ashkanazi Jews have a 1/250 chance of being a carrier of Tay Sachs.
  Your doctor can do a simple blood test to rule out you being a carrier of Tay Sachs, although genitists (doctors who specialize in genetic disorders) will tell you that your partner should be tested as he is the one who is most likely going to be the carrier. Most OB/GYN's test the mother even if it is the father who is the one who is more likely to be a carrier as you are his/her patient and your partner is not. Depending upon your insurance you may choose to be screened for other genetic problems like Cystifc Fibrosis, or Nieman Pic. Even if you and your husband are carriers you can still have children if you use a Reproductive Endocronologist.
• Question:-What are the causes and symptoms of “Tay-Sachs disease”?
  What are the causes and symptoms of “Tay-Sachs disease”?
  Is it common for a particular population?
  What is the Prognosis & Prevention of it?
  
  Answer:-Causes and symptoms:
  Tay-Sachs is caused by a defective gene. Genes are located on chromosomes, and serve to direct specific development / processes within the body. The genetic defect in Tay-Sachs disease results in the lack of an enzyme, called hexosaminidase A. Without this enzyme, gangliosides cannot be degraded. They build up within the brain, interfering with nerve functioning. Because it is a recessive disorder, only people who receive two defective genes (one from the mother and one from the father) will actually have the disease. People who have only one defective gene and one normal gene are called carriers. They carry the defective gene and thus the possibility of passing the gene and / or the disease onto their offspring.
  When a carrier and a non-carrier have children, none of their children will actually have Tay-Sachs. It is likely that 50% of their children will be carriers themselves. When two carriers have children, their children have a 25% chance of having normal genes, a 50% chance of being carriers of the defective gene, and a 25% chance of having two defective genes. The two defective genes cause the disease itself.
  A few variations from this classical progression of Tay-Sachs disease are possible:
  •Juvenile hexosaminidase A deficiency. Symptoms appear between ages two and five; the disease progresses more slowly, with death by about 15 years.
  •Chronic hexosaminidase A deficiency. Symptoms may begin around age five, or may not occur until age 20-30. The disease is milder. Speech becomes slurred. The individual may have difficulty walking due to weakness, muscle cramps, and decreased coordination of movements. Some individuals develop mental illness. Many have changes in intellect, hearing, or vision.
  
  COMMON : Tay-Sachs disease is particularly common among Jewish people of Eastern European and Russian (Ashkenazi) origin. About one out of every 3,600 babies born to Ashkenazi Jewish couples will have the disease.
  
  Prognosis: Sadly, the prognosis for a child with classic Tay-Sachs disease is certain death.
  
  Prevention: Prevention involves identifying carriers of the disease and providing them with appropriate information concerning the chance of their offspring having Tay-Sachs disease. When the levels of hexosaminidase A are half the normal level a person is a carrier of the defective gene. Blood tests of carriers reveals reduction of Hexosaminidase A.
• Question:-Tay-Sachs disease is a recessive genetic disorder that in America predominantly affects people with Eastern ?
  European Jewish ancestry and causes fatal brain damage before the age of five. A man who is heterozygous for Tay-Sachs marries a woman who is also heterozygous for Tay-Sachs. What are the potential genotypes and phenotypes of their offspring? What percentage of their offspring could be expected to suffer from this disease?
  
  Answer:-genotype:TT,2Tt,tt
  phenotype: 1:3
  %=25%
• Question:-Can Tay Sachs disease be detected while a fetus is in utero?
  My friend and I are doing a project for health class and we need to know if the genetic disease Tay Sachs disease can be detected in a baby while it is still in the womb. thanks.
  
  Answer:-Genetic disorders such as Tay-Sachs disease, sickle-cell anemia, and thalassemia meet these criteria, and screening tests are commonly done to identify carriers of these diseases. In addition, screening tests may be done for individuals with family histories of Huntington's disease (a degenerative neurological disease) or hemophilia (a bleeding disorder). Such screening tests can eliminate the need for more invasive tests during a pregnancy.
  
  Read more: Genetic Counseling - Definition, Purpose, Precautions, Description, Preparation, Aftercare, Risks, Normal results, Abnormal results http://health.stateuniversity.com/pages/649/Genetic-Counseling.html#ixzz0Z7pPS3TF
• Question:-If Jewish is only a religion,how come only Jewish people get Tay Sachs?
  I wondered about the disease called Tay Sachs and what percentage of the european Jewish population carries the gene?My grandfather was German Jewish and he was born in 1899,before there was any real outside converts to Judaism.Does that make me a carrier of that disorder,or what are the chances that I am?I also heard that prior to the 20th century,Jews did not mix with other people,thus enhancing my belief that they are a race.So,can anyone tell me how this works?
  
  Answer:-First off Jews are not the only ones who get Tay sachs.
  Both my parents are Jewish as am I. I had a test and I am not a carrier.
  
  It's carriers are from a certain part of the world.
  Try a little research.
  http://www.tay-sachs.org/taysachs_disease.php
  
  Many people now get tested and would choose not to give life to a child who will spend several years dying in pain .
• Question:-Tay Sachs....?
  Is this disease cause by a dominant allele , recessive alleles, extra chromosome or is is sex linked?
  What does it do the the affected person?
  
  Answer:-I think it's recessive alleles. Both parents must be a carrier.
  Infants with Tay-Sachs disease appear to develop normally for the first six months of life. Then, as nerve cells become distended with gangliosides, a relentless deterioration of mental and physical abilities occurs. The child becomes blind, deaf, and unable to swallow. Muscles begin to atrophy and paralysis sets in. Death usually occurs before the age of 4 or 5.
  Extremely rare, Juvenile Tay-Sachs disease usually presents itself in children between 2 and 10 years of age. They develop cognitive, motor, speech difficulties (dysarthria), swallowing difficulties (dysphagia), unsteadiness of gait (ataxia), and spasticity. Patients with Juvenile TSD usually die between 5–15 years.
  A rare form of the disorder, known as Adult Onset Tay-Sachs disease or Late Onset Tay-Sachs disease (LOTS), occurs in patients in their 20s and early 30s. LOTS is frequently misdiagnosed, and is usually non-fatal. It is characterized by unsteadiness of gait and progressive neurological deterioration. Symptoms of LOTS, which present in adolescence or early adulthood, include speech and swallowing difficulties, unsteadiness of gait, spasticity, cognitive decline, and psychiatric illness, particularly schizophrenic-like psychosis. Patients with LOTS frequently become full-time wheelchair users in adulthood, but many live full adult lives if psychiatric and physical difficulties are accommodated. Psychiatric symptoms and seizures can be controlled with medications.
• Question:-Tay sachs?
  Who carries this gene and where does it come from?
  
  Answer:-Tay-Sachs disease is caused by mutations on the HEXA gene on chromosome 15. These mutations reach significant frequencies in several populations. It is most common in Ashkenazi (Eastern European) Jews. Many Cajuns of southern Louisiana carry the same mutation. French Canadians of southeastern Quebec carry a different mutation.
• Question:-Amniocentesis reveals that an embryo has Tay-Sachs disease. What are the genotypes of the parents if they a?
  Amniocentesis reveals that an embryo has Tay-Sachs disease. What are the genotypes of the parents if they appear normal (t = Tay-Sachs)?
  this is college level need help.
  
  Answer:-Sorry it's not a college level answer.
  The problem is caused by an autosomal recessive allele which fails to code for beta-hexosaminidase A.
  If both parents have the normal phenotype, they must both be carriers of the allele, having the genotype Tt
  The Punnett square for this cross yields 1 TT : 2 Tt (carriers) : 1 tt (Tay Sachs sufferer)
  
  John H