What is a Stickler Syndrome?
A group of disorders related to the connective tissue in the human eye is termed as Stickler syndrome. Another disease called Marshall Syndrome which has similar symptoms is considered as a type of Stickler syndrome by some researchers and as a different category of disorders by other researchers. Stickler syndrome is a hereditary disease which is characterized by problems mainly related to eye, ear and problems with bones of face and also joints of the body. Since it is a hereditary disease, may be found within the families (intrafamilial) and also among families (interfamilial). Stickler Syndrome may lead to blindness, hearing loss, increased flexibility of joints and/or causing joint pain or stiffness, back pain due to abnormal curvature of the spinal cord. There are several types of Stickler syndrome found out so far, like Stickler syndrome Type 1, Type 2, Type 3, Type 4, Type 5 and Type 6. These are categorized based on the mutation caused in collagen genes. Out of these, Types 1, 2 and 3 are more prevalent. Types 4, 5 and 6 are found only in a few patients and they are found to be very rare.
Symptoms of Stickler Syndrome
From one research it is found that 80% to 99% of patients who are suffering from Stickler syndrome have one or more symptoms given below.
- Stickler Syndrome Symptom – Ocular Abnormalities. Abnormalities related to eye or vision like progressive myopia, cataract, retinal detachment (vitreoretinal degeneration), and ultimately causing blindness.
- Orofacial Abnormalities. Bones in central part of face is underdeveloped which results in flat face appearance (midfacial hypoplasia), cleft palate, glossoptosis (placement of tongue further back than usual), micrognathia (reduction in size of lower jaw) which makes the person to feel difficulty in breathing.
- Auditory Abnormalities as a Symptom of Stickler Syndrome. Hearing loss may be conductive (change in the middle ear) or sensorineural (change occurred in the inner ear).
- Skeletal Abnormalities. Spondyloepiphyseal dysplasia which means abnormalities at the growing ends of bones of vertebrae in spinal cord which may lead to abnormal curvature of spine causing back pain, premature osteoarthritis (arthritis developed in early life) which may cause joint pain or stiffness, or may cause over flexibility of joints in both children and young adults.
Most of the patients suffering from Type 1 have ocular abnormalities with retinal detachment and auditory abnormalities with hearing loss mainly sensorineural. Type 2 and 3 patients have severe hearing loss. Type 2 have ocular abnormalities also, where as it is not found in Type 3. Hence Type 3 Stickler syndrome is regarded as non-ocular stickler syndrome.
Causes of Stickler Syndrome
The main cause for stickler syndrome is the mutation occurring in different collagen genes viz.,
- Type 1. Mutation in COL2A1
- Type 2. Mutation in COL11A1
- Type 3. Mutation in COL11A2
- Type 4. Mutation in COL9A1
- Type 5. Mutation in COL9A2.
Epidemiology of Stickler Syndrome
Estimation of Stickler syndrome in new borns is from 1 in 7500 to 1 in 9000. It may also be as rare as 1 in 100,000 in some areas of the world. It is mostly seen in second decade of life. Furthermore, the disease is progressive in nature and cataract is developed by the time of fourth decade.
Diagnosis of Stickler Syndrome
The external appearance of the face, problems related to eyes, hearing loss, problems related to joints of the patients of this syndrome guides a doctor to suspect that the person may be suffering from stickler syndrome. It can be diagnosed on the basis of his/her signs and symptoms. Family history also plays a major role in determining this syndrome. Tests would be helpful in confirming the stickler syndrome. The tests may include.
- Imaging Tests. To know the abnormalities of the joints and spinal cord, doctor may advice to take an X-ray.
- Eye Tests. These tests are done by an ophthalmologist to know about cataract, myopia or retinal detachment.
- Hearing Tests for Stickler Syndrome. These tests help the doctor to know any abnormalities related to hearing loss and to know whether it is sensorineural or conductive. This is done by an ENT specialist.
- Molecular Genetic Tests. The patients also may go for molecular genetic tests which include sequence analysis of entire coding region, deletion or duplication analysis, targeted variant analysis and many more. These are helpful to know the inheritance pattern of the patients. By getting the inheritance pattern of patients, it would be easier to know about the chances of occurrence of this syndrome in patient’s future generation.
Treatment of Stickler Syndrome
Before starting the treatment, the doctors confirm whether the patients have some other signs of the stickler syndrome which is not very common, like problems related to heart. Hence, the treatment also varies from person to person. The doctors treat the specific symptoms of each and every person separately. The following treatment methods for Stickler Syndrome may be helpful in betterment of health condition of the patients.
- Cleft palate, cataract and retinal detachment may need surgery.
- Eye drops also help to some extent along with surgery.
- Hearing aids are helpful in hearing loss.
- Joint and bone problems are treated with some medications.
To treat a stickler syndrome patient, many professionals like anesthesiologists, oral and maxillofacial surgeons, audiologists, physiotherapists, craniofacial surgeons, ENT specialists, rheumatologists work in co-ordination with each other.
Prognosis of Stickler Syndrome
Although a forecasting of the probable course and termination of a disease is important, it is somewhat difficult to predict the long-term outlook in case of stickler syndrome. This is because, stickler syndrome has variable symptoms. There may be chances of vision loss, arthritis before 40 years. Sometimes, if the person has mild symptoms of stickler syndrome, he/she may be unaware that he/she may be suffering from stickler syndrome until another member of the family is identified.
Prevention of Stickler Syndrome
If the symptoms of stickler syndrome are detectable easily and in early stage, some steps could be taken as prevention. Or else, if the stickler syndrome symptoms are mild or not taken care in the beginning it may lead to more complications. Some of the preventing steps are listed here .
- Molecular genetic tests help in both confirming the syndrome in an individual as well as helps to know about the possibilities of getting this syndrome in his/her future generations.
- Reduced size of lower jaw may be corrected by mandibular advancement surgeries.
- Timely diagnosis and treatment of abnormalities of eyes can prevent the retinal detachment.
- It is always better to avoid contact lens which may cause trauma in the retina of these patients and also may lead to injury in the eyes.
- Retinal detachment can also be prevented by laser photocoagulation.
Stickler syndrome is a connective tissue disorder which is hereditary. By creating awareness among the people about stickler syndrome, the symptoms, treatment, the prevalence, one can actually prevent children and young adults from worsening the condition. The other family members of the patient who is suffering from stickler syndrome may also go for testing. This also helps to take care of the future generations. The patients are advised for regular follow – ups for their health especially related to ear and eyes since they have hearing and visual impairments. In the patient with stickler syndrome, nutrition support is also needed mainly to bear the weight of retina, to hold it in position, to avoid the retina from falling or slipping. Nutrition may also be helpful in reducing arthritis pain. The nutritionists may also advice to some patients to avoid some foods which are inflammatory in action like lactose and dairy products, wheat protein, gluten, yeast, soya, egg, artificial sweeteners, shellfish, processed meat etc. Some foods are known to reduce inflammation are to be included in the diet. The foods like whole grains, beans, veggies, fruits, oils, seafood, foods containing omega -3-fatty acids are to be taken more.