The more we understand about the symptoms of rare diseases, the more accurate genetic diagnosis becomes.
ORLANDO, Fla. (PRWEB)
July 06, 2021
The more we understand about the symptoms of rare diseases, the more accurate genetic diagnosis becomes. This is especially true for genetic syndromes where the precise cause, or genetic mutation, is often unknown.
Each rare disease, of which there are around 7,000 currently identified, presents with its own unique set of symptoms, or features as they are also often known. These symptoms can range from characteristic facial features, to medical and health conditions, to developmental delay. Symptoms can affect any part of the body and body system, and many rare diseases present with symptoms that affect multiple parts of the body.
Symptoms of a rare disease can range from mild to severe, depending on the rare disease, but also on the individual affected. Sometimes, even siblings or family members with the same rare disease diagnosis, display slightly different symptoms, or symptoms of varying degrees of severity.
Rare diseases are generally not treatable, but many of their symptoms may be, depending on the type and severity. In other instances early intervention may help alleviate a symptom and its impact on an individual’s health and development.
Facial features of a rare disease
Unique facial features are perhaps some of the most well-known, and easily identifiable symptoms of some rare diseases. There are thousands of known facial features associated with rare diseases, and these may affect the shape, size, and even the structure of the relevant part of the face. It may also affect how a part of the face works – a rare disease symptom related to the eye may simply make the eye more prominent, or more widely-spaced, or it may affect an individual’s ability to see as well.
Down syndrome is a rare disease, with some of the most commonly known distinct facial features. This includes a flattened face, specifically across the nose bridge, almond-shaped eyes, a short neck, small ears and related low muscle tone.
Other symptoms of a rare disease
Symptoms of rare diseases can include a wide range of medical and health conditions. Some of these may be congenital, as in present at birth, while others may develop with age. Some of these symptoms may be identifiable during infancy or early childhood, while others may develop in line with puberty, or adulthood.
Some rare diseases are progressive, meaning symptoms and related medical conditions worsen with time.
Medical conditions associated with rare diseases can range from issues affecting the organs of the body – the heart, lungs, liver, kidneys, as some examples. This in turn might cause secondary health issues, such as respiratory and breathing difficulties.
Rare diseases may also present with developmental delay – both physical, mental and emotional/social. Some rare diseases cause global developmental delay, meaning a child shows significant delay in all areas of their development, or it may cause delay in just one area, such as speech or gross motor skills development. In some cases, this developmental delay extends into adulthood and becomes known as a developmental disability, for example, most children diagnosed with Angelman syndrome never learn to talk, or use more than a few words to communicate.
Intellectual development delay, and disability, can also be a symptom or feature of some genetic syndromes. This can range from mild to severe, depending on the syndrome and individual affected.
Genetic diagnosis and symptoms
Genetic counselors have always used an individual’s specific set of symptoms, combined with an understanding of their family medical history, to understand more about the genetic cause of these features.
Genetic testing is very specialized and targeted – there is no one genetic test able to screen an individual’s DNA for any possible genetic or chromosomal change. You need to know what you are looking for, or have a very good idea of which rare disease or genetic mutation you are hoping to identify, in order to understand which genetic test to proceed with.
This is why genetic counselors have also relied on an in-depth understanding of an individual’s symptoms in order to understand which genetic test to recommend. In some cases, with hypermobile Ehlers-Danlos (EDS) where there is no current known genetic cause identified, and so no genetic testing available, genetic experts rely on an individual’s symptoms to diagnose this form of the syndrome.
This can be a complicated process – especially as there are not always objective criteria for measuring a specific symptom. A dependence on a subjective assessment can lead to errors in diagnosis. This is shown with Ehlers-Danlos again, where up to 56% of patients with the syndrome receive a misdiagnosis at some point during their diagnostic journey. The average waiting time for a rare disease diagnosis is around 4-5 years, with Ehlers-Danlos this can increase to 8-10 years.
Rare disease diagnosis and symptoms the future
In recent years there has been an increased awareness of the importance of improving the accuracy and rate of diagnosis for rare disease, even for those with an as yet unknown precise genetic cause.
This has seen the development of advanced AI-powered facial analysis screening to the field of genetic diagnosis. What this new type of genetic analysis does is it scans an image of an individual to identify the unique facial features associated with specific rare diseases. It firstly identifies facial markers of genetic syndromes, and then compares them against an extensive database of known rare disease facial features. From this screening and comparison a genetic analysis report is created. This can then be shared with a genetic counselor, to understand more about an individual’s potential risk for specific rare diseases based on their facial features.
FDNA offers a range of packages for genetic analysis and genetic counseling – most of which can be accessed online, and from the comfort of your own home. Their mission is to provide greater access to genetic counseling, genetic experts, and genetic analysis for those who need it. This includes improving accuracy rates, and ensuring faster and more timely diagnosis for rare diseases ranging from Barber-Say syndrome, to any one of the more than 7,000 genetic syndromes currently identified.