Syndromic telecanthus

What is syndromic telecanthus?

Telecanthus is defined as an increased distance between the medial canthus (the inner corners of the eye) and is generally associated with a genetic disorder (syndromic) rather than appearing alone (isolated).¹ Syndromic telecanthus is associated with other conditions such as Blepharophimosis syndrome, canthus inversus, Mowat-Wilson syndrome or Waardenburg syndrome.¹ Treatment of syndromic telecanthus is generally through surgery of the medial canthus tendons, with diagnosis being through the measurement of the inner canthal distance at birth or use of CT scans, genetic testing and X-rays.² 

Causes of syndromic telecanthus

Syndromic telecanthus can arise from various congenital and acquired factors.³ Congenital factors generally include genetic syndromes such as Down syndrome, Ehlers-Danlos syndrome and Blepharophimosis syndrome, whereas acquired factors can include trauma (facial injuries/fractures) or tumours.³ Since Syndromic telecanthus is an uncommon condition, genetic counselling is important in providing these patients with appropriate management, support and information, allowing patients to understand their condition and make informed medical and personal decisions.⁴ 

Genetic counselling 

What is genetic counselling?

Genetic counselling is an opportunity for an individual to speak with a genetics specialist to help improve their understanding of a genetic condition they suffer from individually or one that runs through their family.⁵ Essentially, it provides an opportunity to understand the impact of a genetic disease on both the individual themself and help make informed decisions about their future (decisions on having children, treatment options, etc.). Individuals suffering from a genetic disease or history of such may be referred to a genetic specialist via their GP.

What happens during genetic counselling?

For patients with syndromic telecanthus, a genetic counselling session would focus on identifying the underlying genetic cause, inheritance risks and creating management options for their condition. During a genetic counselling meeting for an individual with syndromic telecanthus, they can expect a detailed focus on their family history through the use of pedigree trees, a review of possible conditions associated with telecanthus, and a discussion of patient symptoms. In cases of syndromic telecanthus, identifying the underlying genetic cause associated with the disease is crucial to enable both the patient and geneticist to understand appropriate treatment options, in addition to how this condition may affect the patients’ day-to-day life and future; for example, will this condition pass down to their children? Not only does genetic counselling provide an opportunity to identify the cause of disease, but it also allows the patient to understand their individual condition further and provides an opportunity to ask any lingering questions they may have to a professional who understands their disease.

After an initial genetic counselling session, genetic testing options may be suggested to identify specific genes associated with a genetic condition. For example, a counsellor may suggest using single-gene testing to identify a specific gene associated with a telecanthus syndromic condition or whole-exome sequencing for complex cases with unclear syndromic associations. With genetic testing, a genetic counsellor can provide a more concrete diagnosis of what genetic condition is causing the associated syndromic telecanthus. This therefore allows the counsellor to explain the specific syndrome and its medical implications, along with treatment and management options. Understanding which specific condition an individual is affected with also opens the floor to discussions regarding the mode of inheritance of the disease and family planning options. In addition, it also allows for the involvement of specialists for additional evaluation if necessary and the opportunity for family members to be tested to clarify inheritance patterns and risk. 

Syndromic telecanthus management 

Long-term support

Genetic counselling opens a variety of opportunities for patients with syndromic telecanthus to create long-term support and management plans to help manage living with their condition. Medical management for telecanthus can include referrals to specialists such as ophthalmologists, plastic surgeons and neurologists, in addition to having ongoing eye exams, hearing assessments, and neurodevelopmental monitoring if needed. Furthermore, genetic counselling creates an avenue for discussion regarding reproductive counselling. Understanding the effects of a genetic condition and its risk of being present in offspring is highly important, as it allows families to make better decisions regarding their future. For example, individuals can opt for carrier screening and prenatal testing to determine the risk of a genetic disorder, such as Waardenburg syndrome, being passed on to children. Moreover, genetic counselling allows an individual suffering from syndromic telecanthus the opportunity to gain access to psychosocial support, providing opportunities for both emotional counselling and connections to support groups. 

Treatment

Treatment for syndromic telecanthus is mainly committed through surgery, which particularly involves shortening and refixation of the medial canthal tendons. The medial canthal tendons are shortened by a surgeon and secured to a bone that lies between the side of your nose and eye socket.² Tendon shortening and refixation procedure is generally used for congenital telecanthus. In cases of traumatic telecanthus, transnasal wiring is used, whereby a surgeon detaches the medial canthal of the affected eye and repositions it. The tendon is then secured to the skull via a thin wire, which runs through small holes drilled inside the nasal bones and eye sockets. Although transnasal wiring is often used for traumatic telecanthus, it is frequently reported for use in congenital telecanthus.³ As telecanthus is a physical change to facial morphology, there is no reported treatment other than surgery to repair its effects.

Genetic counselling for syndromic telecanthus

Benefits

As discussed prior, genetic counselling provides multiple opportunities for patients with syndromic telecanthus to deepen their understanding of their condition and provide support where necessary. It allows for early intervention of disease and the proposal of personalised medicine strategies to patients to help manage their condition. By addressing medical concerns earlier, this allows for earlier intervention and accessibility to surgery to correct telecanthus, which has been appraised to reduce emotional pressures and body image-related issues.⁶ Moreover, genetic counselling creates an environment for discussion regarding family planning and reproductive decision-making. Having discussions regarding inheritance risk allows for individuals to put fears to rest about whether their condition may be passed down to their offspring. Earlier genetic counselling also allows for the discussion on IVF/fertility treatments, whereby a telecanthus syndromic genetic condition affects the fertility of an individual. 

Challenges and limitations

Though genetic counselling provides great opportunities to help patients understand their future outlook and disease management, multiple challenges and limitations lie ahead of genetic counselling. One general concern with genetic counselling is the risk of ethical dilemmas. While genetic testing for an individual may be required, the need to relay such confidential information to an at-risk family member can result in ethical dilemmas, in which a healthcare professional may question whether they can release sensitive information to help another patient understand their risk towards a condition.⁷ This leads to the question of whether the right to autonomy or privacy outweighs the potential harm of disclosing said information to biological relatives. Moreover, psychological distress is another associated limitation of genetic counselling, whereby a patient learning about their genetic predisposition may develop anxiety, stress or altered self-perception, though this can be supported with referrals to mental health professionals. Furthermore, though genetic testing can be extremely accurate, cases of ambiguous syndromic telecanthus with an unknown cause may also lead to a sense of distress within an individual and a worsened perception of self.     

Summary 

The role of genetic counselling in cases of syndromic telecanthus stands to bridge the gap between an individual’s condition and their understanding of such. It provides opportunities for individuals to gain closure regarding their condition and take a step forward towards better management and treatment of their disease. 

Overall, this article focuses on syndromic telecanthus and discusses in depth the role of genetic counselling with syndromic telecanthus. It highlights the benefits of having access to genetic counselling, which include personalised medicines and a deepened understanding of an individual’s condition, whilst also sharing a limelight on the downsides of genetic counselling. There is no doubt that genetic counselling provides many opportunities for individuals suffering from syndromic telecanthus to understand the genetic cause of their condition, in addition to what effects this has on treatment plans and family planning. However, further advancements in reducing stress induced by counselling, alongside improved testing accuracy and ethical concerns, are required to maximise the benefits of genetic counselling for syndromic telecanthus.