DNA probe is of great value in the identification of gene in all of the following neoplasms except –
**Core Concept**
DNA probes are used in molecular diagnostics to identify specific genes or DNA sequences in various neoplasms. They work by binding to complementary DNA sequences, allowing for the detection of specific genetic mutations or expressions.
**Why the Correct Answer is Right**
The correct answer is related to the principle that DNA probes are particularly useful in identifying genes in neoplasms with specific genetic markers. For instance, DNA probes can be used to detect the BCR-ABL fusion gene in chronic myeloid leukemia (CML) or the HER2/neu gene in breast cancer. However, not all neoplasms have easily identifiable genetic markers, making DNA probes less valuable in their diagnosis.
**Why Each Wrong Option is Incorrect**
**Option A:** DNA probes are indeed useful in the identification of genes in certain neoplasms like CML and breast cancer, making this option incorrect.
**Option B:** Similarly, DNA probes are valuable in detecting genetic mutations in other neoplasms such as acute lymphoblastic leukemia (ALL), making this option incorrect as well.
**Option C:** DNA probes are also useful in identifying genes in certain types of lymphoma, such as follicular lymphoma, which has a characteristic BCL-2 gene rearrangement.
**Clinical Pearl / High-Yield Fact**
One important application of DNA probes is in the detection of genetic mutations in cancer cells, which can help guide treatment decisions. For example, the presence of the BCR-ABL fusion gene in CML can indicate a good response to tyrosine kinase inhibitors.
**Correct Answer: A. ALL**