Carrier Screening Panel
Definition
A test that investigates whether a person is a carrier of autosomal recessive or X-linked diseases. The aim is to determine, before pregnancy or in early pregnancy, the couple's risk of passing a disease on to their children.
Genetiks panels:
| Panel | Coverage |
|---|---|
| Genetiks 180 | Performs comprehensive carrier analysis with a next-generation sequencing panel |
| Genetiks 360 Extended | Together with whole exome sequencing, additionally analyzes SMA, DMD and Fragile X carrier status (in women) |
Why SMA, DMD and Fragile X are analyzed separately: The genetic structure of these three diseases cannot be detected reliably by standard sequencing methods:
- SMA (Spinal Muscular Atrophy): The copy number of the SMN1 gene must be measured (not sequencing)
- DMD (Duchenne Muscular Dystrophy): Large deletions/duplications predominate
- Fragile X: The number of CGG repeats is measured; sequencing cannot read repeat regions
Results
Being found to be a carrier does not mean being ill (see the Carrier entry). The risk arises when the partner is also a carrier for the same disease; in that case there is a 25% chance of an affected child in each pregnancy.
Risks and Limitations
- It provides information for the diseases included in the panel; carrier status for diseases outside the coverage is not detected
- A negative result does not reduce the risk to zero, it only lowers it (residual risk)
- Disease frequencies vary by ethnic background, so the panel's suitability for the target population is important