He Treacher Collins syndrome Is a pathology of genetic origin that affects the development of bone structure and other tissues of the facial area (Genetics Home Reference, 2016).
At a more specific level, although those affected usually present a normal or expected intellectual level for their level of development, they present another series of alterations such as malformations in the auditory ducts and in the ossicles of the ear, palpebral grooves, colobomas ocular or cleft palate, between Others (Mehrotra et al., 2011).
Treacher Collins syndrome is a rare medical condition, so its incidence is estimated to be approximately one case per 40,000 Births, approximately (Rodrigues et al., 2015).
In addition, experimental and clinical studies have shown that, most of the cases of Treacher Collin syndrome, are due to a mutation Present in the Chromosome 5 , Specifically in the 5q31.3 area (Rosa et al., 2015).
As for the diagnosis, this is usually done based on the signs and symptoms present in the affected individual, however, genetic studies Are necessary to specify the chromosomal abnormalities and, in addition, to rule out other pathologies.
Currently, there is no cure for Treacher Collins syndrome, usually medical specialists focus on symptom control Specific in each individual (National Organization for Rare Disorders, 2013).
Therapeutic interventions may include very diverse specialists, as well as different intervention protocols, pharmacological, surgical, etc. (National Organization for Rare Disorders, 2013).
Characteristics of Treacher Collins syndrome
Treacher Collins syndrome is a disorder that affects craniofacial development (OMIN, 2016; Dixon, 1996).
Specifically, the National Association of Treacher Collins Syndrome (2016), defines this medical condition as: "Alteration of the development or cranioencephalic malformation genetic origin congenital, infrequent, incapacitating and without a recognized cure".
This medical condition was first reported in 1846 by Thompson and Toynbee in 1987 (Coob et al., 2014).
However, it is named after British ophthalmologist Edward Treacher Collins, who describes it in 1900 (Mehrotra et al., 2011).
In his clinical report, Treacher Collins, described two children who had abnormally elongated lower eyelids, notches and Cheeks absent or poorly developed (Children's craniofacial association, 2016).
On the other hand, the first extensive and detailed review of this pathology is performed by A. Franceschetti and D. Klein in 1949, using the term dysotosis Mandibulofacial (Mehrotra et al., 2011).
As we have pointed out, this pathology affects the development and formation of the craniofacial structure, so that affected individuals will present Problems, such as atypical facial features, deafness, ocular alterations, digestive problems or Language alterations (National Association of Treacher Collins Syndrome, 2016).
About us
Treacher Collins syndrome is a rare disease in the general population (Genetics Home Reference, 2016).
Statistical studies indicate a prevalence of approximately 1 case per 10,000-50,000 people worldwide (Genetics Home Reference, 2016).
In addition, it is a congenital pathology, so that its clinical characteristics will be present from the moment of birth (National Organization for Rare Disorders, 2013).
As for sex distribution, no recent data indicating a higher frequency in any of these have been found. Moreover, neither There is a distribution associated with particular geographic areas or ethnic groups (National Organization for Rare Disorders, 2013).
On the other hand, this syndrome has a nature associated with de novo mutations and hereditary patterns, therefore, if one of the parents suffers The Treacher Collins syndrome, will present a 50% probability of transmitting this medical condition to their offspring (Chiildren's craniofacial Association, 2016).
In the cases of parents with a child with Treacher Collins syndrome, the probability of having a child with this condition is very low, when The etiological causes are not associated with heritability factors (Chiildren's craniofacial association, 2016)
Characteristic signs and symptoms
There are different alterations that can appear in the children who suffer this syndrome, however, they do not present in a necessary form in all the (Children's craniofacial association, 2016).
The genetic abnormality typical of Treacher Collins syndrome, will cause a wide variety of signs and symptoms, and in addition, all these will affect Primarily to facial skull development (National Organization for Rare Disorders, 2013.
Craniofacial characteristics
- Expensive: Alterations affecting the facial configuration tend to occur symmetrically and bilaterally, that is, in Both sides of the face. Some of the more common anomalies include absence or partial development of cheekbones, incomplete development of Bone structure of the lower jaw, the presence of an anorally small jaw and / or chin.
- Mouth: Cleft palate, mandibular malformations, displacement of the tongue backwards, incomplete development and Misalignment of the dental pieces, are typical alterations in this syndrome.
- Eyes: Malformation or abnormal development of the tissues surrounding the eyeballs, inclination of the eyelids, absence of The eyelids or very narrow tear ducts. In addition, it is also probable the development of slits or muscas in the iris tissue or presence of Abnormally small eyes.
- Respiratory tract: There are many anomalies affecting the airways, the most common of which are the partial development of Pharynx, narrowing or obstruction of the nostrils.
- Ears and ear canals: Malformation of the auditory structures, both internal, middle, and external. Specifically, The ears may not develop or partially, accompanied by a significant narrowing of the external auditory canopy.
- Anomalies in extremities: In a small percentage of cases, people with Treacher Collins syndrome may present Alterations in their hands, specifically, the thumbs may present an incomplete to absent development.
In summary, the alterations that we can expect to appear in children with Treacher Collins syndrome, will affect the mouth, eyes, Ears and breathing (Children's craniofacial association, 2016).
Neurological characteristics
The clinical course of this medical condition will give rise to a particular neurological scheme, characterized by (Coob et al., 2014):
- Variable presence of microcephaly.
- Normal intellectual level.
- Delay in the acquisition of psychomotor skills.
- Variable affectation of cognitive areas.
- Learning problems.
In some cases, delays in the development of various areas or skills acquisition are due to the presence of medical complications and / or Abnormalities or physical malformations.
Secondary medical complications
Alterations in the facial, auditory, buccal or ocular structure will cause a series of significant medical complications, many of which Potentially serious for the affected person (National Organization for Rare Disorders, 2013):
- Respiratory insufficiency : The reduction of the capacity of operation of the respiratory system is a medical condition Potentially fatal for the individual.
- Childhood Apnea : This medical complication supposes the presence of brief episodes of interruption of the respiratory process, especially During the sleep phases.
- Power Problems : Anomalies in the pharynx and oral malformations will seriously hamper the feeding of the Person, the use of countervailing measures will in many cases be essential.
- Loss of vision and hearing: As in previous medical complications, abnormal development of ocular structures And / or hearing systems will result in a variable impairment of both capacities.
- Delay in language acquisition and production : Mainly due to the malformations that affect the speech apparatus.
Of these symptoms, both the presentation / absence and the severity, can vary considerably between the affected persons, even between the Members of the same family.
In some cases, the person affected may have a very subtle clinical course, so that Treacher Collins syndrome may remain to diagnose. In other cases, serious anomalies and medical complications may occur that endanger the survival of the individual (National Organization for Rare Disorders, 2013).
Causes
As we pointed out earlier, Treacher Collins syndrome has a genetic nature of congenital type, therefore, the affected persons Will present this medical condition from birth.
Specifically, a large number of cases are associated with the presence of abnormalities on chromosome 5, in the 5q31 area. (Rosa et al., 2015).
In addition, different investigations throughout the history of this syndrome, have indicated that can be due to specific mutations in the TCOF1 genes, POLR1C or POLR1D (Genetics Home Reference, 2016).
Thus, the TCOF1 gene, is the most frequent cause of this pathology, represents approximately 81-93% of the total cases. On the other hand, the genes POLR1C And POLRD1, give rise to approximately 2% of the remaining cases (Genetics Home Reference, 2016).
This set of genes seem to play a significant role in the development of the bony, muscular and cutaneous structures of the facial areas (Genetics Home Reference, 2016).
Although a good part of the cases of Treacher Collins syndrome are sporadic, this pathology presents a pattern of heritability from parents to children of a fifty%.
Diagnosis
The diagnosis of Treacher Collins syndrome is made based on clinical and radiological findings and, in addition, various genetic tests are used (Genetics Home Reference, 2016).
In the case of clinical diagnosis, a detailed physical and neurological examination is followed in order to specify them. Normally, this process is Based on the diagnostic criteria of the disease.
One of the tests most used in this evaluation phase are the X-rays , These are able to offer us information about the presence / absence Of craniofacial malformations (National Organization for Rare Disorders, 2013).
Although certain facial features are directly observable, X-rays give accurate and accurate information about bone development Jaws, skull development, or the development of additional malformations (National Organization for Rare Disorders, 2013).
In addition, in cases where the physical signs are still very subtle or in which it is necessary to confirm the diagnosis, several tests may be used To confirm the presence of mutations in the TCOF1, POLR1C and POLR1D (National Organization for Rare Disorders, 2013) genes.
In addition, when there is a family history of Treacher Collins syndrome, it is possible to perform a prenatal diagnosis. Through the amniocentesis We can examine the genetic material of the embryo.
Treatment
There is currently no curative treatment for Treacher Collins syndrome, so experts focus on the treatment of signs and symptoms. Most common symptoms.
Thus, the initial confirmation of the pathology, it is essential that an evaluation of the possible medical complications is performed (Huston Katsanis & Wang Jabs, 2004):
- Airway disorders
- Severe alterations of facial structure.
- Buccal crevices.
- Swallowing disorders.
- Additive alterations.
- Eye and vision problems.
- Dental anomalies.
The concretion of all these anomalies is fundamental for the design of an individualized treatment and adjusted to the needs of the person Affected.
Thus, the management of this individualized treatment usually requires the presence of professionals from different areas such as pediatrician, surgeon Plastic, dentist, audiologist, speech therapist, psychologist, etc. (Huston Katsanis & Wang Jabs, 2004).
Specifically, all medical complications are divided into several temporal phases to address their medical therapeutic intervention (Huston Katsanis & Wang Jabs, 2004):
- 0 to 2 years : Treatment of alterations in the airways and resolution of feeding problems
- From 3 to 12 years : Treatment of language disorders and integration in the education system
- 13 to 18 years old : Use of surgery for the correction of craniofacial malformations.
In all these phases, both drug use and chyritic reconstruction are the most common therapeutic techniques (National Organization for Rare Disorders, 2013).
References
- ANSTC. (2016). What is Treacher Collins? Obtained from National Association of Treacher Collins Syndrome.
- CCA. (2010). Guide to understand the treacher-collins syndrome. Retrieved from the Children's Craniofacial Association.
- Cobb, A., Green, B., Gill, D., Ayliffe, P., Lloyd, T., Bulstrode, N., & Dunaway, D. (2014). The surgical management of Treacher Collins syndrome. British Journal of Oral and Maxillofacial Surgery , 581-589.
- Genetics Home Reference. (2016). Treacher Collins syndrome. Retrieved from the Genetics Home Reference.
- Huston Katsanis, S., & Wang Jabs, E. (2012). Treacher Collins Syndrome. GeneReviews .
- Mehrotra, D., Hassan, M., Pandey, R., & Kumar, S. (2011). Clinical spectrum of Treacher Collins Syndrome. Journal of Oral Biology and Craniofacial Research , 36-40.
- Rodrigues, B., Oliveira Silva, J., Gualberto Guimarães, P., Formiga, M., & Pavan Viana, F. (2015). Evolution of a child with Treacher Collins syndrome undergoing physiotherapeutic treatment. Fisioter. Mov. , 525-533.
- Rosa, F., Bebiano Coutinho, M., Pinto Ferreira, J., & Almeida Sousa, C. (2016). Ear malformations, hearing loss and hearing rehabilitation in children with Treacher Collins syndrome. Acta Otorrinolaringol Esp. , 142-147.