Achondroplasia (ACH) is the most common form of short-limb dwarfism occurring in 1 in 15,000-28,000 births and appears to be slightly more prevalent in females, but indiscriminate towards breed (1 -3). Evidence of cases of ACH dating back as far as 4500 BC has been found in Egypt (4). In simpler terms, ACH is a disease in which shrinkage of bones formed into cartilage occurs (5). There are many features that accompany this disease, including rhizomelic (proximal) shortening of the extremities, megalencephaly (enlarged brain), short stature, trident hand, and forehead prominence (prominent forehead) (1, 3, 4 , 6-8). Expression of this gene at high levels is found primarily in cells of the nervous system, cartilage rudiments, and chondrocytes in the growth plates of developing bone ( 7 , 9 ). Since there are numerous types of skeletal dysplasia, some of which sometimes appear similar to ACH, the only way to have complete confirmation is to perform molecular techniques such as genetic testing (1, 4, 8). The gene responsible for this disease, FGFR3, is located on chromosome 4 at address 16.3, which is located on the short arm near the telomere (4). Under normal circumstances, this gene forms fibroblast growth receptor 3, which interacts with a protein to initiate a flow of signals that contribute to the development and maintenance of bones; it is also believed that this gene is also important in the development of other tissues (6, 7, 10-12). Some of the known pathways involved with FGFR3 are STAT1/3, STAT5, MEK1, ERK1, and MAP kinase signaling. Chondrogenesis and osteogenesis are two processes controlled by these pathways and are strongly influenced by mutation (13-15). Sections of these pathways that involve and are affected by mut… middle of paper… interfere with binding to receptors. The last possibility uses CNP, which downregulates the activation of MAP kinase pathways in chondrocytes (4). ACH is an interesting disease, which after many years of research still remains a partial mystery. The fact that a single nucleotide on a chromosome can affect an individual so much is astonishing, especially when combined with the fact that this mutation is so homogeneous in genotype and phenotype. As more and more skeletal dysplasias are linked to FGFR3, research has increased to fully determine and define the pathways involved with this gene. The reason for such a high mutation frequency and the link with paternal age is also being studied. Once we have a greater understanding of how this mutation affects the body, we may be able to find treatments and possibly cures for these individuals.