There are a lot of elements in which different human beings can differentiate themselves. As far as physics is concerned, some of the clearest and most obvious examples are the colour or properties of the eyes, hair or skin or weight or height.
Unlike aspects such as personality or different cognitive abilities, these characteristics are determined mainly at the genetic level, as is the case with the propensity to suffer from certain diseases . In fact, it is not uncommon for some conditions of genetic origin to give rise to unusual phenotypes or body forms.
An example of this is achondroplasia , one of the main causes of the condition known as dwarfism. And it is about this genetic alteration and its different effects that we will talk about throughout this article.
What is achondroplasia?
It is called achondroplasia a a disease of genetic origin which is one of the main causes of dwarfism worldwide .
Although it is relatively well known among the population, the truth is that it is considered a rare disorder, occurring only in about 2.5 out of every 100,000 births in Spain and 1 out of every 25,000 births worldwide. This is a chondrodysplasia , a type of alteration which implies irregularities or delays in the formation of cartilage.
In the case of achondroplasia, throughout the development of the subject, a problem is generated in the cells that allow bone growth and the transformation of cartilage into bone. This leads to accelerated calcification of the bones, which prevents the bones, especially those in the extremities, from developing to the usual size.
This means that achondroplasia generates rhizomelic dwarfism (in the bones of the forearm and thigh), in which the trunk has normative measures while the extremities stop growing lengthwise .
Another symptom of achondroplasia is macrocephaly, with frontal prominence and midface hypoplasia. This means that generally people who suffer from this alteration have a head of relatively large dimensions compared to the rest of the body, as well as a more prominent forehead or front of the face .
Brachydactyly also appears, so that the fingers and toes and their bones are much shorter than usual (although generally and except for some cases it does not have to affect the functionality of the hand), and hyperlordosis or extreme curvature of the spine.
Far from being a condition that affects only visually or aesthetically, achondroplasia is a condition that can lead to a host of health problems and complications . Although there is usually no intellectual impairment (achondroplasia per se does not generate cognitive impairment), there is usually a certain delay in the development of motor skills.
There is also often hypotonia and greater ease of fatigue. It is also not uncommon for problems such as obstructive sleep apneas to appear, as well as otitis that can affect auditory perception. Also there is a greater risk of neurological and cardiovascular problems s, as well as a tendency towards obesity. Finally, achondroplasia sufferers are often at greater risk of respiratory infections and conditions.
More serious but also less frequent are disorders such as compression of the spine and the increased possibility of suffering from hydrocephalus (an excess or accumulation of fluid in the brain that could threaten the life of the subject or that could lead to intellectual disability). In fact, there is a relevant risk of mortality during the infant stage due to this type of complication, as well as due to airway obstruction. In homozygous cases, achondroplasia is usually lethal already during the fetal period.
However, if no complications occur, the life expectancy and intellectual capacity of people with achondroplasia is no different from that of the rest of the population without this disorder.
Difficulties in other vital areas
Achondroplasia is not only a health problem, but can also lead to various difficulties in daily life, impairing the quality of life of the affected person.
For example, most infrastructures or even furniture are usually designed for people with a much larger stature , so the simple fact of sitting on a chair or driving a car represents a difficulty unless you have the appropriate supports.
It is also common for people with achondroplasia to tend to fatigue more easily, which may make it difficult to perform various activities both at work and in leisure.
The quality of sleep for these people may be diminished if they have obstructive apnea. In the event of pregnancy, women with achondroplasia often need a C-section due to the small size of their pelvic bones.
In addition to this and especially during child and adolescent development, people with this disorder may encounter difficulties at a social level and suffer isolation, harassment, ridicule, humiliation or simply unwanted attention from others. Likewise, and as a consequence of this, in some cases, problems of anxiety or depression may also appear.
Causes of this alteration
Achondroplasia is, as we have seen before, a medical condition of genetic origin. Specifically, mutations have been observed in the FGFR3 gene (on the short arm of chromosome 4), which is the fibroblast growth factor receptor 3.
This gene participates in the growth of bones and the transformation of cartilage into bone , and its mutation generates the aforementioned accelerated calcification of bones and a blockage of their growth due to insufficient differentiation of the tissue.
Although it may be inherited, and usually in parents with achondroplasia there is a 50% risk of passing it on and having autosomal dominant inheritance, the vast majority of cases are usually de novo re-emerging mutations. That is, generally appears as a spontaneous mutation in the subject’s genome , without the parents having to suffer the same problem.
Do you have treatment?
Achondroplasia is a medical condition of genetic and congenital origin and as such has no curative treatment. However, treatment is possible and may be necessary from a multidisciplinary approach in order to correct possible complications and prevent the appearance of disabilities or difficulties in daily life, both in children and adults.
To begin with, in the case of hydrocephalus or spinal cord compression, it is essential to act as quickly as possible in order to correct the problem and avoid serious complications or dysfunctions, using surgical interventions if necessary. The objective would be to reduce intracranial pressure and/or drain excess fluid in the case of hydrocephalus or decompress and correct spinal problems. Sometimes growth hormone treatment has been used, as well as interventions to correct the curvature of the extremities.
Beyond the treatment described so far, it will be very important to include physiotherapy and the performance of exercises and practices to stimulate mobility and allow the adjustment and strengthening of posture and muscles. It may also be necessary to work on fine and gross psychomotor skills, in order to facilitate the development of basic day-to-day skills.
In some cases it may be necessary to work on speech therapy, especially if there are hearing or phonatory problems. Nutrition should also be worked on in order to prevent possible cardiovascular or respiratory problems that could appear in the case of obesity or poor nutrition.
Finally, also at the psychological level professional intervention may be necessary, especially when there are anxious or depressive symptoms .
Self-esteem and self-concept, cognitive restructuring to modify dysfunctional beliefs, stress and anger management or the presence of difficulties in daily life derived from both physical problems and possible problems at the social level can be worked on. Enhancing self-esteem and autonomy is also very helpful.
At the educational level, the help that these people may need should be offered, so that they can perform and integrate in these areas. The provision of adjusted aids may include the use of support material or the curricular adaptation of the person. Also on a labour level, persons with achondroplasia may require adaptations , mainly linked to the ergonomics and physical difficulties of these persons.
- Krakow, D. (2018). FGFR3 disorders: thanatophoric dysplasia, achondroplasia, and hypochondroplasia. In: Copel JA, D’Alton ME, Feltovich H, et al, eds. Obstetric Imaging: Fetal Diagnosis and Care. 2nd ed. Philadelphia, PA: Elsevier:chap 50.
- NIH (2017). Achondroplasia. Medline Plus. [Online]. Available at: https://medlineplus.gov/spanish/ency/article/001577.htm.
- Orphanet Inserm (2017). Achondroplasia. Orphanet Encyclopedia of Disability. [Online]. Available at: https://www.orpha.net/data/patho/Han/Int/es/Acondroplasia_Es_es_HAN_ORPHA15.pdf.