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Testing the disease-causing gene for mutations that are common in a specific ethnic group - autosomal recessive diseases
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It is preferable to start by testing patients in the family, if there are any.
If the defects (mutations) are found using this method, it is possible:
- To allow a couple that has had an affected child to undergo prenatal diagnosis to determine
with a high degree of reliability whether subsequent fetuses are healthy or affected.
- To establish which family members carry the mutation and are therefore considered to
be carriers but not affected. Family members found to be carriers will be at risk for
having an affected child if their partners are also carriers, and therefore their partners
should also undergo testing for carrier status.
If a patient cannot be examined: Family members,
or a fetus, may be directly tested for the presence of the common mutations.
However, the reliability of the test in such cases is reduced, depending on the percentage of
patients with these mutations in the particular ethnic group (degree of coverage or percentage
of detection of the mutations tested).
In such cases, it is recommended that partners of family members found to be carriers also
undergo tests for carrier status.
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