Which genetic mutation is linked to Achondroplasia?

The correct answer is FGFR3, which stands for Fibroblast Growth Factor Receptor 3. Achondroplasia is primarily caused by a specific mutation in the FGFR3 gene. This gene plays a crucial role in the regulation of bone growth, and mutations lead to abnormal cartilage formation and impaired endochondral ossification, resulting in the characteristic features of achondroplasia such as disproportionate short stature and specific skeletal abnormalities.

The mutation in FGFR3 typically results in a glycine-to-arginine change at position 380 of the protein, which causes the receptor to become overly active. This excessive activity inhibits the proliferation and function of growth plate chondrocytes in the long bones, leading to the growth deficiencies observed in individuals with achondroplasia.

Other genes listed, such as ALPL, SLC26A2, and RUNX2, are associated with different genetic conditions. For instance, mutations in ALPL are linked to hypophosphatasia, SLC26A2 mutations are related to diastrophic dysplasia, and RUNX2 mutations are associated with cleidocranial dysostosis. These conditions have distinct phenotypes and underlying mechanisms that are not related to the etiology of achondroplasia.