Creutzfeldt Jakob syndrome
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Types and clinical signs
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Creutzfeldt Jakob syndrome is a degenerative disease of the brain. The cause is
not always genetic, and some people have been infected by injection of brain products
(growth hormone that used to be extracted from brains) into their blood or by ingestion
of uncooked brain products, which used to be a custom in some parts of Africa.
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Inheritance pattern
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Autosomal dominant.
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Penetrance
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Almost always complete, but age dependent. The mean age at which the mental degeneration
starts is 60 years. By the age of 80, 96% of the carriers of the mutation are affected.
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Associated features that can be demonstrated in tests performed during pregnancy
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There are usually no defects. This condition cannot be diagnosed in pregnancy in
a family that does not already have affected children.
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What is the risk of recurrence in a subsequent pregnancy?
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A parent carrying the mutation has a 50% chance in every pregnancy of transmitting
it to his or her offspring.
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Molecular genetic information
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The gene for the disease
PrP gene.
Location
???
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Genetic testing
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Diagnostic testing
The mutation E200K is tested for in families with affected individuals. See information
sheet: Testing the disease-causing gene for mutations
that are common in a specific ethnic group - autosomal dominant diseases.
Carrier testing
Carrier testing is in fact the same as diagnostic testing - see above.
Fetal testing
See in section on diagnostic testing.
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