This makes estimates of prevalence difficult, with changing and subjective diagnostic criteria over time. One detailed and long-running study in the Netherlands found that the prevalence determined at birth was only 1.3 per 100,000 live births. Another study at the same time found a rate of 1 per 10,000. A 2020 review and meta-analysis estimated a worldwide prevalence of 4.6 per 100,000. Research
As of 2019, tentative evidence has found that the experimental peptide drug vosoritide increases growth velocity in those with achondroplasia. The drug inhibits the activity of FGFR3. Animals
Based on their disproportionate dwarfism, some dog breeds traditionally have been classified as "achondroplastic". This is the case for the dachshund, basset hound, corgi and bulldog breeds. Data from whole genome association studies in short-limbed dogs reveal a strong association of this trait with a retro-gene coding for fibroblast growth factor 4 (FGF4). Therefore, it seems unlikely that dogs and humans are achondroplastic for the same reasons. However, histological studies in some achondroplastic dog breeds have shown altered cell patterns in cartilage that are very similar to those observed in humans exhibiting achondroplasia.A similar form of achondroplasia was found in a litter of piglets from a phenotypically normal Danish sow. The dwarfism was inherited dominant in the offspring from this litter. The piglets were born phenotypically normal, but became more and more symptomatic as they reached maturity. This involved a mutation of the protein collagen, type X, alpha 1, encoded by the COL10A1 gene.
Diagnosis
Achondroplasia can be detected before birth by prenatal ultrasound, although signs are often subtle and not apparent before the 24th week of pregnancy. A DNA test can be performed before birth to detect homozygosity, wherein two copies of the mutant gene are inherited, a lethal condition leading to stillbirths. Postnatal diagnosis of achondroplasia is typically uncomplicated, involving an assessment of physical and radiographic features. Clinical features include megalocephaly, short limbs, prominent forehead, thoracolumbar kyphosis and mid-face hypoplasia. Complications like dental malocclusion, hydrocephalus and repeated otitis media can be observed. The risk of death in infancy is increased due to the likelihood of compression of the spinal cord with or without upper airway obstruction. Radiologic findings
A skeletal survey is useful to confirm the diagnosis of achondroplasia. The skull is large, with a narrow foramen magnum, and relatively small skull base. The vertebral bodies are short and flattened with relatively large intervertebral disk height, and there is congenitally narrowed spinal canal. The iliac wings are small and squared, with a narrow sciatic notch and horizontal acetabular roof. The tubular bones are short and thick with metaphyseal cupping and flaring and irregular growth plates. Fibular overgrowth is present. The hand is broad with short metacarpals and phalanges, and a trident configuration. The ribs are short with cupped anterior ends. If the radiographic features are not classic, a search for a different diagnosis should be entertained. Because of the extremely deformed bone structure, people with achondroplasia are often "double jointed".