**Core Concept**
The FLT3 gene, also known as the Fms-like tyrosine kinase 3 gene, is a crucial regulator of hematopoiesis and is involved in the development of various hematological malignancies. The FLT3 gene encodes a receptor tyrosine kinase that plays a significant role in the proliferation and survival of hematopoietic cells.

**Why the Correct Answer is Right**
The correct answer, **13q12**, is the chromosomal location of the FLT3 gene. This gene is located on the long arm of chromosome 13, specifically at band 13q12. The FLT3 gene is involved in the TKD (tyrosine kinase domain) mutation, which is a common mutation in acute myeloid leukemia (AML). This mutation leads to the constitutive activation of the FLT3 receptor, resulting in uncontrolled cell proliferation and survival.

**Why Each Wrong Option is Incorrect**
**Option B:** 11q23 is the chromosomal location of the MLL gene, which is involved in acute leukemia, particularly infant acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML).
**Option C:** 11p13 is the chromosomal location of the WT1 gene, which is involved in Wilms tumor, a type of kidney cancer that occurs in children.
**Option D:** 4q24 is not a recognized chromosomal location associated with the FLT3 gene or any other well-known gene involved in hematological malignancies.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the FLT3 TKD mutation is a significant prognostic factor in acute myeloid leukemia (AML), with patients harboring this mutation having a poorer outcome compared to those without the mutation.

**✓ Correct Answer: A. 13q12**