What is progeria?
Progeria, also known as Hutchinson-Gilford progeria syndrome (HGPS), is a rare genetic condition that causes rapid aging in children. It occurs in both sexes.
Progeria has a very low incidence rate occurring in an estimated 1 per 8 million live birth worldwide.
Most kids with progeria hardly attain maturity usually they do not live past mid teens or early twenties.
Progeria can not be inherited, or passed down in families. Because it occur as a new mutation and carriers hardly live to reproduce.
Symptoms of progeria
Children with progeria appear normal when they're born, but they start to show signs of the disease during their first year. They do not grow or gain weight normally. They develop physical traits including:
Wrinkled face
Big head
Large eyes
Small lower jaw
Thin nose with a "beaked" tip
Ears that stick out
Veins you can see
Slow and abnormal tooth growthigh-pitched voice
Loss of body fat and muscle
Hair loss, including eyelashes and eyebrows
Hardening and tightening of the skin on trunk and extremities of the body,
Other symptoms include:
Kidney failure,
Loss of eyesight,
Atherosclerosis and cardiovascular problems
Note: Mental development is not affected in progeric children.
Causes of progeria
LMNA is a gene that codes for a structural protein called prelamin A.
Under normal conditions there is a farnesyl functional group which attaches to the carboxyl-terminus of the protein structure.
The farnesyl group allows prelamin A to attach temporarily to the nuclear rim. Once the protein is attached, the farnesyl group is removed. Without its farnesyl group, prelamin A is referred to as lamin A.
Lamin A, along with lamin B and lamin C, makes up the nuclear lamina, which provides structural support to the nucleus.
But under abnormal conditions the farnesyl group remain attached to the prolamin A making it to permanently affix to the nuclear rim which result to abnormally formed Lamin A called Progerin responsible for premature aging.
Healthy nucleus progeric nucleus
This abnormaity was discovered to be due to a point mutation in position 1824 of the LMNA gene, in which C (cytosine) is replaced with T (thymine).
This mutation creates a 5' cryptic splice site within exon 11, resulting in an abnormally short mature mRNA transcript.
This mRNA strand, when translated, yields an abnormal variant of the prelamin A protein whose farnesyl group cannot be removed.
Because its farnesyl group cannot be removed, this abnormal protein, referred to as progerin, is permanently affixed to the nuclear rim, and therefore does not become part of the nuclear lamina.
Without lamin A, the nuclear lamina is unable to provide the nuclear envelope with adequate structural support, causing it to take on an abnormal shape. Since the support that the nuclear lamina normally provides is necessary for the organizing of chromatin during mitosis, weakening of the nuclear lamina limits the ability of the cell to divide.
Though progerin, is linked to normal aging, but is produced in healthy individuals via "sporadic use of the cryptic splice site"
TREATMENT OF PROGERIA
Though many attempts has been made to treat progeria but no treatment has proven effective.
Most treatment focuses on reducing complications associated with it.
REFERENCE: https://en.m.wikipedia.org/wiki/Progeria
REFERENCE: https://en.m.wikipedia.org/wiki/Progeria
Progeria, also known as Hutchinson-Gilford progeria syndrome (HGPS), is a rare genetic condition that causes rapid aging in children. It occurs in both sexes.
Progeria has a very low incidence rate occurring in an estimated 1 per 8 million live birth worldwide.
Most kids with progeria hardly attain maturity usually they do not live past mid teens or early twenties.
Progeria can not be inherited, or passed down in families. Because it occur as a new mutation and carriers hardly live to reproduce.
Symptoms of progeria
Children with progeria appear normal when they're born, but they start to show signs of the disease during their first year. They do not grow or gain weight normally. They develop physical traits including:
Wrinkled face
Big head
Large eyes
Small lower jaw
Thin nose with a "beaked" tip
Ears that stick out
Veins you can see
Slow and abnormal tooth growthigh-pitched voice
Loss of body fat and muscle
Hair loss, including eyelashes and eyebrows
Hardening and tightening of the skin on trunk and extremities of the body,
Other symptoms include:
Kidney failure,
Loss of eyesight,
Atherosclerosis and cardiovascular problems
Note: Mental development is not affected in progeric children.
Causes of progeria
LMNA is a gene that codes for a structural protein called prelamin A.
Under normal conditions there is a farnesyl functional group which attaches to the carboxyl-terminus of the protein structure.
The farnesyl group allows prelamin A to attach temporarily to the nuclear rim. Once the protein is attached, the farnesyl group is removed. Without its farnesyl group, prelamin A is referred to as lamin A.
Lamin A, along with lamin B and lamin C, makes up the nuclear lamina, which provides structural support to the nucleus.
But under abnormal conditions the farnesyl group remain attached to the prolamin A making it to permanently affix to the nuclear rim which result to abnormally formed Lamin A called Progerin responsible for premature aging.
This abnormaity was discovered to be due to a point mutation in position 1824 of the LMNA gene, in which C (cytosine) is replaced with T (thymine).
This mutation creates a 5' cryptic splice site within exon 11, resulting in an abnormally short mature mRNA transcript.
This mRNA strand, when translated, yields an abnormal variant of the prelamin A protein whose farnesyl group cannot be removed.
Because its farnesyl group cannot be removed, this abnormal protein, referred to as progerin, is permanently affixed to the nuclear rim, and therefore does not become part of the nuclear lamina.
Without lamin A, the nuclear lamina is unable to provide the nuclear envelope with adequate structural support, causing it to take on an abnormal shape. Since the support that the nuclear lamina normally provides is necessary for the organizing of chromatin during mitosis, weakening of the nuclear lamina limits the ability of the cell to divide.
Though progerin, is linked to normal aging, but is produced in healthy individuals via "sporadic use of the cryptic splice site"
TREATMENT OF PROGERIA
Though many attempts has been made to treat progeria but no treatment has proven effective.
Most treatment focuses on reducing complications associated with it.
REFERENCE: https://en.m.wikipedia.org/wiki/Progeria
REFERENCE: https://en.m.wikipedia.org/wiki/Progeria
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