Multiple sclerosis |
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Types and clinical signs ( Multiple sclerosis symptoms ) |
In this disease there is localized damage in the white matter of the brain that manifests in
neurological deficits corresponding to the region of the brain where the damage has occurred.
The disease occurs paroxysmally (in attacks) and two episodes each lasting more than 24 hours with
an interval of more than a month between them are needed to establish the diagnosis.
The neurological deficits are diverse.
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Inheritance pattern |
Multifactorial - there is a genetic basis, and an environmental trigger, such as a
particular virus, may lead to the onset of the disease in genetically predisposed individuals.
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Penetrance |
Not known.
Women are affected twice as often as men.
The age of onset in most affected individuals is between the ages of 20 and 40 years.
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Associated features that can be demonstrated in tests performed during pregnancy |
None.
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What is the risk of recurrence in a subsequent pregnancy?
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The brother of a female with multiple sclerosis has a 2.5% chance of having
the same condition.
Conversely the sister of an affected male has a 5% risk.
The brother of a male with multiple sclerosis has a 4% chance of having the same condition.
Conversely the sister of an affected male has a 3% risk.
The identical twin of an affected individual has a 25% chance of also being affected.
Conversely, a non-identical twin has the same risk as any other sibling - 2%.
The risk for children of a patient suffering from the disease is 2.5% irrespective of sex.
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The risk for more distant relatives depends on the number of affected individuals in the
family, the degree of relationship between the relatives and the affected individuals, etc.,
and is established within genetic counseling.
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Molecular genetic information |
The gene for the disease and its location
One of the genes is situated, as in type 1 diabetes, in the region of the tissue matching (HLA) gene
complex on chromosome 6.
Research is continuing in an attempt to find additional genes - mainly genes in the immune system -
one of which is the gene PTPPRC on chromosome 1q31, in which mutations have been found in families
of patients.
These findings have not yet been proved and are not part of the standard clinical investigation,
but serve as a marker.
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Genetic testing |
Diagnostic testing
In multiple sclerosis there are currently no reliable molecular tests.
In specific families with many patients, it is possible to consider linkage analysis
(see: Indirect testing for
genetic markers in a family that has one or several patients - when there are a number of
different genes that can each cause the disease - the gene, or most of the genes not having
been located / identified / mapped - multifactorial diseases.
Carrier testing
There is no reliable carrier test for multiple sclerosis.
Fetal testing
There are no diagnostic molecular tests that can be performed in the fetus or newborn.
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What is Multiple Sclerosis
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