Which of the following gene is associated with caudal dysgenesis?

The DNA binding domain is called the T-box, and there are more than 20 genes in the T-box family. Thus, mesoderm formation in these regions depends on this gene product, and its absence results in shoening of the embryonic axis (caudal dysgenesis). The degree of shoening depends on the time at which the protein becomes deficient. Ref: Langman's embryology 11th edition Chapter 5.