A. Based on clinical features and specific features on radiographs, the diagnosis of achondroplasia is made. The radiography may show contracted base of the skull, a square shape of pelvis with small sacrosciatic notch, rhizomelic dwarfism, trident hands & proximal femoral radiolucency. Hypochondroplasia and thanatophoric dysplasia, though similar to achondroplasia, can be distinguished as hypochondroplasia is usually milder and than thanatophoric dysplasia is usually severe & lethal.

Q: How is the disease treated?

A. In the newborn, the condition can be diagnosed by radiographic studies. Special achondroplasia growth curves and infant development charts are available from which expected adult height could be estimated. Serial arm span, head circumference, total body length and upper to lower body segment ratio should be evaluated. Since, hydrocephalus may develop during the 1^st 2 years, head circumference should be monitored every monthly for the first year and every 3 monthly in the second year. If the head circumference increases rapidly, a cranial ultrasound may be required at 2, 4 or 6 months of age to evaluate the ventricular size. After 6 months, neuroimaging may be required. The same may be required if the infant shows asymmetrical reflexes, extreme hypotonia or early hand preference. Then the patient should be referred to a pediatric neurosurgeon for shunting. Development of thoracolumbar kyphosis has been found to be associated with unsupported sitting before there is adequate trunk muscle strength. Parents should be instructed to avoid carrying such a child in a curled-up position. They should provide back support for the first year of life. If kyphosis does not disappear even after the child starts walking (usually it disappears) then it can be corrected by a brace or with surgery. Patients with achondroplasia have a small foramen magnum, which may rarely cause cord compression at the cervicomedullary junction leading to breathing difficulty and paralysis. Foremen magnum decompression may be required. Bowing of the legs may occur due to fibular overgrowth at the ankles & knee. If the bowing leads to an inability to walk, surgical correction may be required.Speech should be evaluated latest by 2 years of age. If speech is abnormally delayed conductive hearing loss due to otitis media should be ruled out. Untreated, it can lead to conductive hearing loss.Patients with achondroplasia may also have obstructive sleep apnea due to flattened mid facial profile between 1 - 5 years. If upper airway obstruction is suspected, polysomnographic studies may be required.Dental crowding and malalignment of teeth may require orthodontic bracing and removal one or two teeth after 5 years of age.In mid to late childhood, children are prone to obesity and their eating habits should be evaluated. The child should avoid gymnastics and contact sports because of the potential for neck or back damage and cause spinal compression. To decrease the lumbar lordosis, the child should be encouraged correct posture. These children have another wise normal and productive life.

Q: How is achondroplasia detected antenatally ?

A. The diagnosis may be suspected by ultrasound on the basis of disproportionately short limbs in the fetus. Genetic testing can be done if both the parents have achondroplasia. Such homozygous infants are either stillborn or die shortly after birth. Such pregnancies should be followed by ultrasound at 14, 16, 18, 22 and 32 weeks of gestation to distinguish homozygosity from normal growth in the fetus.

Q: What precautions should a mother with achondroplasia take during pregnancy?


A. An expectant achondroplasic mother should undergo delivery by cesarean section due to a small pelvis. The mother should be given general anesthesia and not spinal/epidural anesthesia as the mother may develop complications due to spinal stenosis. A baseline pulmonary function study should also be done as the mother may develop respiratory compromise in the third trimester of pregnancy.

Q: How can achondroplasia be prevented ?

A. It cannot be prevented in majority of cases as 75 % of them occur as new mutations. However prenatal screening for achondroplasic parents can be offered.

Last created on 23-02-2001
Last updated on 28-04-2007