For TRDs, what is the preferred testing strategy?

The preferred testing strategy for identifying translocation-related disturbances (TRDs) typically involves PCR with reflex to Southern blotting. This approach is effective because PCR allows for the amplification of specific regions of DNA that may contain translocations or rearrangements. By using PCR, genetic counselors can target areas of interest quickly and efficiently, which is especially important when the specific genes or regions involved in the translocation are known or suspected.

If the initial PCR results indicate the presence of a translocation, further confirmation is obtained through Southern blotting. This technique allows for the visualization and verification of the size and presence of specific DNA segments, providing more details about the genetic rearrangement. The combination of these methods gives a high level of specificity and sensitivity needed for accurate diagnosis.

In contrast, whole exome sequencing might include a broader range of genetic variants but lacks the specificity required for detecting specific translocations directly. Single gene mutation screening is often limited to known mutations in a specific gene rather than the broad range of rearrangements that may occur in TRDs. Chromosomal karyotype analysis can reveal major chromosomal abnormalities but may not detect smaller or more specific translocations as effectively as PCR and Southern blotting. Thus, the combination of PCR with reflex to Southern blot remains the