What is Oral Facial Digital Syndrome?
Oral Facial Digital Syndrome is essentially, a genetic disorder that mostly affects development in the facial region, the oral area (mouth and teeth), fingers, and toes. Oral facial digital syndrome is actually a broad term for at least 13 identified genetic disorders that are known to affect the face, the mouth, and the digits (fingers and toes).
There is significant variation in the different disorders classified under the term, due to the different symptoms for each disorder. This makes the process of accurate diagnosis increasingly difficult.
General Signs and Symptoms of Oral Facial Digital Syndrome
There are certain general symptoms that make it easier to identify whether a patient is suffering from some variant of the disorder. A person may be suffering from a variant of Oral facial digital syndrome if he/she exhibits any combination of signs and symptoms from the list below:
- Eyes that are widely apart or staring in different directions
- Cleft lip
- A lobed or split tongue
- Lateral, under, or over bite
- Tongue tumors
- Missing or additional teeth
- Hair loss
- Unusually small jaw
- A broad nose, either at the base or the tip
- Angled ears
- Extra fingers and/or toes
- Webbed feet or hands
- Bent and rigid fingers
- Mental retardation of different degrees
- Slower development of speech and motor control
- Growth retardation
- Malfunctioning heart or kidneys
- Sunken chest.
Types of Oral Facial Digital Syndrome Disorders
Currently, there are a total of 13 disorders covered under the umbrella term of Oral facial digital syndrome1. Each disorder has its own specific name, and exhibits different signs and symptoms. The name, description, and symptoms of each disease are given in the following list:
- Oral Facial Digital Syndrome (OFDS) type I disease: This disease is also referred to as the Papillon-Leage-Psaume Syndrome. This disease affects the oral cavity, facial features, and fingers and toes. It is also known to cause polycystic kidney disease. Oral facial digital syndrome type I is known to be caused my mutation in the gene OFD1, which plays a key role in development of the brain, limbs, face, and kidneys in the early stages. It is possible to diagnose this disease at birth, but it has also been diagnosed in adulthood. OFDS type 1 may exhibit symptoms such as tongue tumors, missing teeth, lobed tongue, webbed or abnormally curved fingers/toes. People may also show signs of kidney problems. This diseases is known to be lethal in males, however, most individuals carrying it are females.
- OFDS Type-II Disease (Mohr Syndrome): People with Mohr Syndrome tend to exhibit signs of bumps on the tongue, a split lip and/or palate, and an unusually wide nasal bridge which causes widely spaced eyes. Their fingers and toes may be short and narrow, or they may have extra fingers and/or toes. Mohr Syndrome is a genetic condition, but the exact gene that causes it has not been identified.
- OFDS Type-III disease (Sugarman Syndrome): A genetic disease, carriers of the syndrome exhibit round faces with full cheeks, hypertelorism (increased distance between eyes), inwards turned eyes, myoclonic eye twitching, forward rounding of the back, and severe spasticity.
- OFDS Type-IV disease (Baraitser-Burn Syndrome): Features specific to this disease include non-cancerous tumors developing on the tongue, polydactyly (extra fingers or toes), extreme clubfoot, and a shortened middle portion of the lower leg. The cause of the disease appears to be a mutated tectonic family member 3 gene.
- OFDS Type-V Disease (Thurston Syndrome): While the gene that causes it has not yet been identified, this is yet another genetic disease. Very few occurrences of this have been reported, keeping in line with the rarity of the Oral Facial digital syndrome overall. Common symptoms of this disease have been identified as cleft lip, extra little fingers, cleft tongue, and other abnormalities in the upper lip.
- OFDS Type-VI disease (Varadi-Papp Syndrome): A syndrome that usually starts at infancy, the Varadi-Papp syndrome is also simply referred to as the Varadi syndrome. Typical findings of this disease include a lobulated tongue, tumorlike overgrowth, and in some cases, cleft lip and/or palate. This disease is genetic in nature and affects both males and females equally.
- OFDS Type-VII disease (Whelan Syndrome): The Whelan syndrome, is one of the rarest diseases on this list and is primarily associated with dysfunction in the kidneys of people.
- OFDS Type-VIII Disease (Edwards Syndrome): Also known as trisomy 18, Edwards’ syndrome has been known to cause a wide range of severe medical problems. Commonly found in infants, most babies who suffer from this die before or soon after birth. Babies who survive till adulthood are likely to have severe mental and/or physical disabilities. Symptoms of the Edwards’ Syndrome include low birth weight, small jaw, smooth feet with rounded soles, a cleft lip and palate. Babies with Edwards’ syndrome are also prone to have heart diseases, breathing problems, hernias in the stomach, abnormal bone structures, and severe learning disabilities.
- OFDS Type-IX Disease (OFD Syndrome with Retinal Abnormalities): Type 9 disease is typically characterized by a high arched palate, with a lobed tongue, mild intellectual deficit, and specific retinal abnormalities (such as retinal dysplasia).
- OFDS Type-X Disease (OFD with Fibular Aplasia): Also known as the Figuera syndrome, the onset of this disease can be traced to infancy. It is typically characterized by facial and digital features such as extraordinary radial shortening, and coalescence of the tarsal bones. Only one case of this disease has been registered across history in a 10-month girl.
- OFDS Type-XI Disease (Gabrielli Type): The onset of this stage is at the neonatal stage. This is one of the rarest and most sporadic forms of OFDS. This disease is primarily characterized by blepharophimosis, broad nasal bridge, low set ears, and fused vertebrae as well as critical intellectual disabilities, deafness, and congenital heart defects.
- OFDS Type-XII Disease (Moran-Barroso Syndrome): This disease is characterized by abnormalities in the cardiac and/or nervous system, in addition to the oral, facial, and digital malformations prevalent in the other diseases.
- OFDS Type-XIII Disease (Degner Syndrome): With onset at the Neonatal stage, people carrying this disease show signs of cardiac and/or neuropsychiatric manifestations such as tricuspid valve dyslexia and epilepsy. Leukoaraiosis is also associated with the Degner Syndrome.
Causes of the Oral Facial Digital Syndrome
The different types of Oral facial digital syndrome diseases are known to have different causes. While researchers have been able to determine that Oral Facial digital syndrome diseases are genetic in nature, they have been unable to identify specific genes for certain diseases which are passed down. Researchers are of the opinion that the mutation in genes that causes the diseases is random and sporadic, which is why the Oral Facial digital syndrome is relatively uncommon. Genetic diseases are often determined by the combinations of genes of a particular trait that are passed down to a child from a parent. Types II, III, IV, V, VI, and IX are believed to have been caused by autosomal recession, which refers to a situation when babies inherit the same abnormal gene as their parent1. Thus, if a parent has had symptoms of Oral Facial digital syndrome, it is highly likely that the infant will be diagnosed as well. Some types are caused by X-linked recession, which is when conditions are caused by an abnormal gene found on the X-chromosome. If a male’s X-chromosome is carrying the gene, then the male is almost certain to catch the disease. For a female, if one of the X chromosomes is carrying the gene, it can be turned off.
The Oral Facial digital syndrome is extremely rare, with Type I (Papillon-Leage-Psaume Syndrome) being the least rare. OFDS I is believed to be found between 1 per 50000 and 1 per 250000 births1.
It is not possible to prevent the occurrence of Oral Facial digital syndrome due to its causes being genetic.
Diagnosis of the Oral Facial Digital Syndrome
Currently, it is only possible to accurately diagnose Oral Facial Digital Syndrome Type I (Papillon-Leage-Psaume), which can be confirmed using genetic testing. There are no known ways of diagnosing any of the other types of Oral Facial Digital Syndrome. Usually, diagnosis is attempted on the basis of the symptoms that are presented.
Cure of Oral Facial Digital Syndrome
The Oral facial digital syndrome may be cured using reconstructive surgery for incidents such as facial clefts. Genetic counseling is recommended, however, most of the treatment is primarily symptomatic and supportive.
The Oral facial digital syndrome is an extremely rare disease and it can manifest in many forms. Due to its genetic causes, it is not possible to prevent it from occurring, however, there are treatments for certain situations where reconstructive surgery can be helpful. In some cases, the disease, however, can be lethal, as is the case for males suffering from Papillon-Leage-Psaume syndrome and thus increased awareness about Oral Facial Digital Syndrome is required.
- Bruel, A., Franco, B., Duffourd, Y., Thevenon, J., Jego, L., & Lopez, E. et al. Fifteen years of research on oral–facial–digital syndromes: from 1 to 16 causal genes. Journal Of Medical Genetics, (2017). 371-380. doi: 10.1136/jmedgenet-2016-104436