What is the gene product associated with Achondroplasia?

• A. Pax6 transcription factor
• B. Fibroblast growth factor receptor-3
• C. LDL receptor
• D. Huntingtin

Answer: (B)

The gene product associated with Achondroplasia is Fibroblast Growth Factor Receptor-3 (FGFR3). Achondroplasia is a common form of dwarfism caused by a mutation in the FGFR3 gene, which is located on chromosome 4. This gene encodes a receptor that is involved in the regulation of bone growth and development, particularly in the conversion of cartilage to bone.

When the FGFR3 receptor is mutated, it leads to an altered signaling pathway that inhibits the growth of bones, particularly long bones, which results in the characteristic short stature seen in individuals with Achondroplasia. The mutated FGFR3 protein is often hyperactive, which means it sends inhibitory signals for bone growth even when it shouldn't, leading to impaired endochondral ossification.

Therefore, recognizing FGFR3 as the gene product directly associated with Achondroplasia is essential for understanding the molecular basis of this genetic condition. The other choices represent different genes or gene products that are not involved in the pathophysiology of Achondroplasia.