Achondroplasia

• Achondroplasia (dwarfism) is characterized by a disorder of bone growth.
• Most common form of short limb dwarfism first reported in 1878.¹ 
• Occurs in 1 in every 15,000 to 1 in 40,000 live births.
• Caused by a gene mutation of a protein that is involved in converting cartilage to bone.
• Most people who have the condition have average-sized parents.
• Other people inherit the condition from a parent who has achondroplasia.² 
• Most will have a normal or near-normal life expectancy.
• Increased risk of premature death related to cardiovascular complications in mid-adult life.³ 
• No cure is available.⁴ 

Symptoms

• Small stature
• Short limbs
• Macrocephaly
• Midfacial retrusion (underdevelopment of the bones of the face resulting in flattening of the entire midface and nasal bridge)
• Small chest
• Thoracolumbar kyphosis
• Lumbar hyperlordosis
• Limited elbow extension
• Short fingers and trident configuration of the hands
• Hypermobile hips and knees
• Bowing of the legs
• Hypotonia⁵ 

Complications

• Middle ear infections
• Obstructive sleep apnea (more than 50% of patients)
• Pulmonary complications
• Brainstem compression and intracranial hypertension
• Sudden infant death (rare)
• Ventriculomegaly
• Hydrocephaly (rare)
• Obesity
• Back pain
• Peripheral nerve compression⁴ 

Impact on Occupations

• Delayed development of gross motor and ambulatory skills are more common than delays in early communication, fine motor, and feeding skills seen in children.⁶ 
• ADLs and self-care
• School participation

Treatment

• No specific treatment is available.
• Patients are monitored for growth and potential complications.² 
• Surgical limb lengthening may improve body proportions but has a high rate of complications.⁷ 
• No medications or supplementation are recommended.⁸ 

Outcome Measures

• Functional Independence Measure for Children (WeeFIM) ⁹ 

Occupational Therapy

• Health management to avoid obesity in early childhood.
• Provide interventions for socialization and social adjustment.¹⁰ 
• Promote an increase in functional skills and independence (self-care skills).
• Provide interventions for motor and postural deficits.¹¹ 
• Provide strategies to address bullying (including on cyberbullying social media).
• Provide psychosocial interventions for depression, anxiety, drug use, and suicide ideation.⁸ 
• Provide strategies to maintain independence with ADLs, transfers, locomotion, and stairs.⁹ 
• Enhance client’s perception of self-image and increase self-esteem.
• Educate parents about avoiding risky physical activities and sports: trampoline use, vaulting in gymnastics, diving off diving boards, sparring in martial arts, football, rugby, downhill skiing, heading in soccer. Violent neck movement creates the most risk and helmets are not preventative.
• Parents should continue using rear-facing car seats for as long as tolerated.
• Prevent injuries and harm due to seizures.
• Promote rest and sleep and refer to specialists for obstructive sleep apnea and breathing problems.
• Provide good back support and emphasize prone positioning (“tummy time”) to reduce the risk of kyphosis progression.
• Low back and lower abdominal muscle strengthening and pelvic rotations may diminish the severity of hyperlordosis (personal author observation).
• Practice proper body mechanics to minimize spinal complications.
• Pain management with rest, warmth, massage, and NSAIDS may help for knee hypermobility.
• Avoid activities that induce subluxation in the shoulders, e.g., butterfly stroke in swimming and dead-lifting of weights.
• Prescribe adaptive device for function such as for limited elbow ROM.
• Humeral lengthening may be effective to maintain function with perineal hygiene.
• Allow extra time and provide alternatives to handwriting due to wrist hypermobility: free-flowing pens and markers, larger grips, wrist stabilizing braces.
• Promote comfortable seating in school with modifications to ensure proper feet and back support.
• Children can be taught to perform perineal hygiene by getting off the toilet, bending forward, and reaching between the legs, and wiping from front to back. Commercial toileting aids may be helpful.
• Vehicles may be modified to accommodate the physical limitations of using hand controls and foot pedals.
• Educate on energy conservation techniques for limited endurance and chronic pain to minimize dependence on helpers.⁵ 
• Modify the environment and place frequently used things in easier-to-reach places.
• Allow more time to take tests in school.¹² 

1. Parrot JM. Sur les malformations achon­droplasiques et le dieu Ptah. Bull Anthropol Paris. 1878;1:196.[↩]
2. National Human Genome Research Institute. (2016). About Achondroplasia. Retrieved from https://www.genome.gov/Genetic-Disorders/Achondroplasia[↩][↩]
3. Wynn J, King TM, Gambello MJ, Waller DK, Hecht JT. Mortality in achondroplasia study: a 42-year follow-up. Am J Med Genet A. 2007;143A:2502–11.[↩]
4. Unger, S., Bonafé, L. & Gouze, E. Current Care and Investigational Therapies in Achondroplasia. Curr Osteoporos Rep 15, 53–60 (2017). https://doi.org/10.1007/s11914-017-0347-2[↩][↩]
5. Pauli, R.M. Achondroplasia: a comprehensive clinical review. Orphanet J Rare Dis 14, 1 (2019). https://doi.org/10.1186/s13023-018-0972-6[↩][↩]
6. Ireland, P. J., Donaghey, S., McGILL, J. A. M. E. S., Zankl, A., Ware, R. S., Pacey, V., … & Johnston, L. M. (2012). Development in children with achondroplasia: a prospective clinical cohort study. Developmental Medicine & Child Neurology, 54(6), 532-537.[↩]
7. Donaldson J, Aftab S, Bradish C. Achondroplasia and limb lengthening: results in a UK cohort and review of the literature. J Orthop. 2015;12:31–4.[↩]
8. Pereira, E. (2019). Achondroplasia. Pediatrics in review, 40(6), 316-318.[↩][↩]
9. Ireland, P. J., Mcgill, J., Zankl, A., Ware, R. S., Pacey, V., Ault, J., … & Johnston, L. M. (2011). Functional performance in young Australian children with achondroplasia. Developmental Medicine & Child Neurology, 53(10), 944-950.[↩][↩]
10. National Center for Advancing Translational Sciences. (2013). Achondroplasia. Retrieved from https://rarediseases.info.nih.gov/diseases/8173/achondroplasia[↩]
11. Ireland, P. J., Johnson, S., Donaghey, S., Johnston, L., Ware, R. S., Zankl, A., … & McGill, J. (2012). Medical management of children with achondroplasia: evaluation of an Australasian cohort aged 0–5 years. Journal of paediatrics and child health, 48(5), 443-449.[↩]
12. Pfeiffer, K. M., Brod, M., Smith, A., Gianettoni, J., Viuff, D., Ota, S., & Charlton, R. W. (2021). Assessing physical symptoms, daily functioning, and well‐being in children with achondroplasia. American Journal of Medical Genetics Part A, 185(1), 33-45.[↩]