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Screening test for identifying defects (mutations) using various methods such as
SSCP – autosomal recessive diseases
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The test is performed on the patients themselves – even if there is only one. The
gene can be screened for a mutation without checking each and every one of its component
bases. This is a short, simple and more rapid test than establishing the entire
gene sequence. However, this method can identify only some mutations. If the defect
is found using this method, it is possible:
- To allow a couple who 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. However, gene sequence
testing on the partner is not simple – it is expensive, time-consuming, and not
completely reliable. Carrier testing involving examining the entire gene sequence
is not routinely performed.
If a patient cannot be examined:
It is impractical (but possible) to check family members (or the fetus) directly
using the same methods, which are time-consuming and complex.
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