TaySachs Disease

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Tay-Sachs Disease

• By Jill Meltzer

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Tay-Sachs Disease

• (TSD)
• One of the most well known Jewish genetic disease
• Affects one in every 2,500 Ashkenazi Jewish
  newborns
• Three forms of the disease
• Infantile-onset form (Well-known)
• Chronic GM2- gangliosidosis (Lesser known
  late-onset or adult form)
• Juvenille

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Children that died from Tay-Sachs
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Genetic

• Chromosome 15
• Problems with creating the enzyme Hexosaminidase
  A which helps break down certain lipids in the
  brain
• Causes a buildup of nerve cells in the brain
  which then affects the brainstem
• Autosomal recessive
• For a carrier couple there is a 25 (1 in 4
  chance) that the pregnancy will be affected by
  Tay-Sachs

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Punnett Square for Tay-Sachs Disease

• These two heterozygous parents are carriers to
  Tay-Sachs disease (note both parents must be
  carriers). The autosomal recessive (tt)
  offspring will be affected by the disease.
• There is also a 50 chance the offspring will be
  a carrier of Tay-Sachs (Tt).

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Punnett Square Visual
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Symptoms of the Disorder(and Additional Health
Problems)

• Clearly visible cherry-red spot in the back of
  the eye
• Developmental delays
• 10-14 months old child may have trouble with
  focusing and tracking their eyes.
• Trouble balancing themselves
• Difficulties with speaking
• Eventually, the nervous system becomes so
  affected that the body cannot support the life.
• Tay-Sachs is most commonly found in children, but
  the symptoms of the disease can also occur in
  adults or teens in a later stage of life.

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Cherry-red Spot on Eye
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Detection of Carriers

• Measurement of hexosaminidase A in plasma or
  white blood cells can help determine if someone
  is a carrier of the disease.
• Also can detect carriers through enzyme and gene
  mutation analysis prior to pregnancy (which can
  help a couple decide if they should have kids).

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Prenatal Diagnostic Testing

• There are two types of prenatal diagnosis
• CVS
• chronic villus sampling procedure used for
  prenatal diagnosis involves putting a needle
  through the abdomen into fingerlike projections
  of the placenta known as chronic villi.
• Aminocentesis
• Procedure used for prenatal diagnosis Insertion
  of a needle through the abdomen into the amniotic
  fluid
• To this point, approximately 2,500 pregnancies
  have been monitored.

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Prognosis and Treatment

• Children usually die by age 5.
• Tay-Sachs is fatal and results in death.
• Currently, there is no cure or effective
  treatment for Tay-Sachs.

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Current Research

• There is worldwide research being done to find an
  effective treatment or cure for Tay-Sachs
  Disease.
• Researchers are exploring many Therapeutic
  approaches to find a treatment for Tay-Sachs.
• i.e. gene therapy, enzyme replacement therapy,
  stem cells

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Genetic Counseling

• Approximately 1,100 carrier couples are counseled
  for their 25 chance to have a Tay-Sachss child.
• A genetic counselor might help a couple decide
  whether or not they should have children knowing
  that there is the chance that their child could
  have Tay-Sachs.

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My Little Girl Will Never Grow Up

• This story is about a baby named Beth that was
  diagnosed with Tay-Sachs Disease. This story
  tells about how the family coped with Beths
  illness and how they attended support groups to
  learn how to properly take care of her.
• The couple also had another daughter, Kelly, who
  did not have Tay-Sachs. This shows that even
  though a couple may have one child that has
  Tay-Sachs, there is still the chance they can
  have normal and non-affected kids.
• To read more go to http//domin.dom.edu/faculty/
  craigdav/N20SC160/Boyce-Hagerty.html

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Credits

• http//www.mssm.edu/jewish_genetics/diseases/tay-s
  achs.shtml
• http//www.ntsad.org/
• http//domin.dom.edu/faculty/craigdav/N20SC160/Bo
  yce-Hagerty.html
• http//www.discerngenetics.org/images/6.1.gif
  -punnet square visual
• http//www.kellogg.umich.edu/theeyeshaveit/congeni
  tal/images/tay-sachs.jpg -cherry-red spot picture
• http//www.geocities.com/deanfamlee/angels.html
  -children that died from Tay-Sachs