Biology

1. PROGERIA
(Hutchinson-Gilford Progeria Syndrome)

2. What is progeria?
 It is a progressive genetic disorder that causes children to age
rapidly, beginning in their first two years of life.
 Children with progeria generally appear normal at birth. By 12
months, signs and symptoms, such as slow growth and hair
loss, begin to appear.
Signs of progeria may include:
 Loss of body fat and muscle
 Early signs of skin aging
 Stiffness in the joints
 Hip dislocation
 Visible veins
 Generalized atherosclerosis, leading to cardiovascular
and heart disease

3.  The average life expectancy for a child
with Progeria is about 13, but some with
the disease die younger and some live 20
years or longer.

4. How is Progeria inherited?
 Researchers have discovered a single gene
mutation responsible for Progeria.
 HGPS is caused by a mutation in the gene
called LMNA. Researchers now believe
that the defective Lamin A protein makes
the nucleus unstable.
 The cellular instability appears to lead to
the process of premature aging in
Progeria.

5. What chromosomes does it affect?
 HGPS is “sporadic autosomal dominant”
mutation.
 It affects chromosome 1. It is a
substitution mutation in one allele of
chromosome 1.
 The allele that is substituted is usually a
cytosine and it is substituted by a thymine.

6. Treatments:
 There is no known cure for Progeria
 The child usually just takes medication to
get rid or to slow down the symptoms of
Progeria.

9. TAY-SACHS DISEASE

10. Classic Infantile Juvanile Late Onset
Symptoms usually occur
when the child is about
6months old.
Symptoms begin to occur
sometimes during
childhood.
Adults with Late Onset
Tay-Sachs may have first
showing signs during their
childhood, such as speech
impediments or just not
being very athletic or
strong.
It starts out with slowed
development and the
gradual loss in skills such
as coordination,
swallowing and breathing
and reduced vision.
Early symptoms include
slurred speech, muscle
weakness, swallowing and
breathing difficulties.
Symptoms that occur
during adulthood maybe
muscle weakness and
mental health problems.
These then progress into a
decline in mobility and
breathing swallowing
difficulties.
By the time the child has
reached 2 years of age, they
may experience seizures as
well as loss of mental and
muscle functions.
Later symptoms include a
decline or loss in the ability
to walk, eat and
communicate and are very
prone to respiratory
diseases, pneumonia and

11. Diagnosis:
 Children with infantile Tay-Sachs are
often diagnosed by a characteristic “red
dot” found on the retina of the eye.
 Tay-Sachs is a hereditary disease, so in
order to get it both parents must be
carriers of the gene.

12. Causes:
 A defective gene on chromosome 15 (HEX-A) causes
Tay-Sachs disease. This defective gene causes the
body to not make a protein called hexosaminidase A.
Without this protein, chemicals called gangliosides
build up in nerve cells in the brain, destroying brain
cells.
 The disease is hereditary, which means it is passed
down through families. You have to receive two
copies of the defective gene — one from each parent
— to become affected. If only one parent passes down
the defective gene, the child becomes a carrier. They
will not be affected, but may pass the disease down to
their own children.

13. Treatments:
 Unfortunately, there is no cure for Tay-
Sachs yet but there are ways of making
life more comfortable for those living
with the disease such as:
-massage therapy
-feeding tubes
-wheelchairs, canes and walkers
-support groups to provide help and care to
families and those suffering from the disease