Achondroplasia: symptoms, causes and treatments

This is a disease of genetic origin associated with various forms of dwarfism.

There are a large number of elements in which different human beings can be differentiated. In terms of physique, some of the clearest and most obvious examples are the color or properties of the eyes, hair or skin, or weight or height.

In contrast to aspects such as personality or different cognitive abilities, these characteristics are mainly determined at the genetic level. are mainly determined 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 shapes.

An example of this is achondroplasiaone of the main causes of the condition known as dwarfism. And it is about this genetic alteration and its different effects that we are going to talk about in this article.

What is achondroplasia?

It receives the name of achondroplasia to 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 an alteration considered rare, occurring in only about 2.5 out of every 100,000 births in Spain and 1 out of every 25,000 births worldwide. It is a chondrodysplasiaa type of disorder that involves irregularities or delays in the formation of cartilage.

Symptoms

In the case of achondrodysplasia, throughout the development of the subject, a problem is generated in the cells that allow bone growth and the transformation of cartilage to bone. This causes an accelerated calcification of the bones that prevents them, especially those of the extremities, from developing to the usual size.

This results in achondroplasia generating rhizomelic dwarfism (in the bones of the forearm and thigh), in which the trunk has normative measurements while the limbs stop growing lengthwise..

Another symptom of achondroplasia is macrocephaly, with frontal bossing and hypoplasia of the middle third of the face. This means that generally people suffering from this disorder have a head of relatively large dimensions compared to the rest of the body, as well as a forehead or front part of the face that is larger than the rest of the body. a more prominent forehead or front of the face..

It also appears brachydactyly, so that the fingers and toes and their bones are much shorter than usual (although generally and except in some cases does not necessarily affect the functionality of the hand), and hyperlordosis or extreme curvature of the spine.

Far from being a condition that affects only visual or aesthetic level, the truth is that achondroplasia is an alteration that can generate a large number of health problems and complications.. Although there is usually no intellectual alteration (achondroplasia per se does not generate alterations at the cognitive level), the truth is that there is usually a certain delay in the development of motor skills.

There is also usually hypotonia and greater ease of fatigue. In addition, it is not uncommon for problems such as obstructive sleep apneas to appear, as well as otitis that can affect auditory perception. Also there is an increased risk of neurological and Cardiovascular problems, as well as a tendency to obesity.and cardiovascular problems, as well as a tendency to obesity. Finally, people with achondroplasia are often at increased risk of infections and respiratory disorders.

More serious, but also less frequent, are disorders such as spinal cord compression and the increased possibility of hydrocephalus (an excess or accumulation of fluid in the brain that could threaten the life of the subject or could lead to intellectual disability). In fact, there is a significant risk of mortality during infancy due to this type of complications, 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 are no different from those of the rest of the population without this disorder.

Difficulties in other vital areas

Achondroplasia does not only affect health, but can also imply the appearance of different difficulties in daily life, impairing the quality of life of the affected person.

For example, most of the infrastructures or even furniture are usually designed for people with a much larger stature, so that the simple fact of having to use a wheelchair can have a negative impact on the quality of life of the person affected.For example, most infrastructures or even furniture are usually designed for people who are much taller, so that simply sitting in a chair or driving a car is a difficulty unless they have adequate support.

It is also common that people with achondroplasia tend to become fatigued more easily, something that can make it difficult to carry out various activities, both at work and at leisure.

The quality of sleep of these individuals may decrease if they suffer from obstructive apnea. In case of pregnancy, women with achondroplasia often need to resort to cesarean section, due to the small size of their pelvic bones.

In addition, and especially during childhood development and adolescence, people with achondroplasia may find that their pelvic bones are too small, people with this disorder may encounter difficulties at the social level and suffer from isolation, bullying and suffer isolation, harassment, ridicule, humiliation or simply unwanted attention from others. Likewise, and as a consequence, in some cases, anxiety or depression problems may also appear.

Causes of this disorder

Achondroplasia is, as we have seen previously, a medical condition of genetic origin. Specifically, it has been observed the presence of mutations in the FGFR3 gene (on the short arm of the FGFR3 chromosome). gene (on the short arm of chromosome 4), which is the fibroblast growth factor receptor 3.

This gene is involved in bone growth and the transformation of cartilage into bone.Its mutation is responsible for the accelerated calcification of the bones and for blocking their growth due to insufficient tissue differentiation.

Although it can be hereditary, and usually in parents with achondroplasia there is a 50% risk of transmitting it and having autosomal dominant inheritance, in general the vast majority of cases are usually new onset de novo mutations. That is, it usually appears as a spontaneous mutation in the genome of the subject, and the parents do not have to have it.The parents do not necessarily have to have the same problem.

Is it treatable?

Achondroplasia is a medical condition of genetic and congenital origin and as such has no curative treatment. and as such it has no curative treatment. However, treatment from a multidisciplinary approach is possible and may be necessary in order to correct possible complications and prevent the onset 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 to correct the problem and avoid complications or serious dysfunctions, using surgical interventions if necessary. The aim would be to reduce intracranial pressure and/or drain excess fluid in case of hydrocephalus or decompress and correct spinal problems. Growth hormone treatment has sometimes been used, as well as interventions to correct limb curvature.

In addition to the treatment described so far, it will be very important to the inclusion of physiotherapy and the performance of exercises and practices to stimulate mobility and allow to adjust and strengthen posture and musculature. and allow adjustment and strengthening of posture and musculature. 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 case of obesity or poor diet.

Finally, psychological at the psychological level, professional intervention may be necessary, especially when there are anxious or depressive symptoms..

Work can be done on 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 social problems. Enhancing self-esteem and autonomy is also of great help.

At the educational level, the aids that these people may need should be offered, in order to allow their performance and integration in these areas. The provision of adjusted aids may include the use of support material or the curricular adaptation of the person. Also at the work level, people with achondroplasia may require adaptations, mainly related to ergonomics., mainly linked to ergonomics and the physical difficulties of these persons.

Bibliographic references:

• 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 from: https://www.orpha.net/data/patho/Han/Int/es/Acondroplasia_Es_es_HAN_ORPHA15.pdf.