Stickler syndrome is a progressive genetic disease of the connective tissue that causes abnormalities with vision, hearing and skeletal development. The name comes from Dr. G. B. Stickler, who initially described the condition in 1965. It is mostly diagnosed during infancy or childhood, and is usually not tied to learning or other intellectual disabilities. Patients with Stickler syndrome may suffer from hearing loss, retinal detachments and loose joints. Poor facial development can also result in a flat-looking face with a small nose and chin. Children can also develop features of Pierre Robin sequence, which include a cleft palate (opening in the roof of the mouth), an enlarged tongue and a shrunken lower jaw. There is no cure for Stickler syndrome, but treatment is available for managing the symptoms.
Causes and Risk Factors
Stickler syndrome is caused by a genetic error, or mutation, in genes that produce collagen - the building blocks of connective tissue. The three main collagen genes associated with this condition are COL2A1, COL11A1 and COL11A2, which carry the genetic instruction for producing collagen for the eye and joints.
Stickler syndrome is inherited as an autosomal dominant condition. This means anyone with Stickler syndrome has a 50% chance of passing down the disease to each of his or her offspring. A less common, autosomal recessive form of the disease is associated with the COL9A gene. In this case, a child must inherit two mutated copies of the gene, one from each parent, to develop Stickler syndrome. These genes do not account for every form of Stickler syndrome, and some first-time cases are due to a random gene mutation that is not present in either parent.
The symptoms of Stickler syndrome vary. Even affected members in the same family can experience symptoms with varying severities. Known symptoms include:
Vision abnormalities: Severe nearsightedness is one of earliest signs of Stickler syndrome. Inadequate collagen inside the eye can also lead to retinal detachments, glaucoma and cataracts.
Hearing challenges: Hearing loss, especially with high frequency sound waves, and frequent ear infections are associated with Stickler syndrome.
Skeletal and joint problems: Stickler syndrome causes a range of developmental problems in the face, spine and joints. These include a shorter stature due to abnormal spine curvature, overly flexible joints and early onset of osteoarthritis. Abnormal musculoskeletal development in the face can cause a flattened face with a smaller-than-average nose and chin. A cleft palate is present in some infants.
Heart valve defect: Roughly 50% of children with Stickler syndrome have a poorly functioning heart valve.
Diagnosis and Treatment
Stickler syndrome is diagnosed based on a physical exam and a review of the patient’s medical history. Genetic tests are also available to detect mutations in some collagen-producing genes.
Genetic testing: Tests that look for mutations in the COL2A1, COL11A1 and COL11A2 genes can assist in diagnosing the autosomal dominant form of Stickler syndrome. Since the associated mutations for all forms of the disease are not known, other tests are necessary for an accurate diagnosis. Genetic counselors can help patients understand the test results and cope with emotional challenges that may arise.
Vision tests: Eye exams help to detect abnormalities of the retina or the jelly-like substance inside the eye. The exams also look for glaucoma, cataracts and nearsightedness, which is a common feature of Stickler syndrome.
Hearing exam: These tests check for the patient’s ability to hear sounds in varying volume and pitch.
Imaging test: Imaging tests (e.g., X-ray) produce a picture of the skeletal system and allow physicians to inspect the spine and joint health.
Although there is no cure for Stickler syndrome, the symptoms can be managed with treatment. Early treatment and continuous monitoring in young children is critical in order to prevent blindness, deafness, difficulty breathing or eating, and other complications.
Medications: Over-the-counter drugs help alleviate joint pain and stiffness. Patients with glaucoma may require daily medicated drops to relieve pressure inside the eye.
Speech therapy: Children who experience hearing loss at a young age may require speech therapy to pronounce some sounds. Hearing aids can also help improve language and socialization skills.
Special education: Vision and auditory challenges can affect how well children learn in school. Special programs that are focused on a child’s unique needs can help.
Face/neck surgery: Surgery can be used to address some of structural abnormalities in the face. A tracheostomy allows infants with obstructed breathing to breathe normally through a temporary hole in the neck. Surgical procedures for lengthening the lower jaw or correcting a cleft palate are also available.
Eye surgery: Patients with glaucoma and cataracts may require corrective surgery to prevent blindness.
Ear tube placement: Children with Stickler syndrome acquire frequent ear infections. Placing a short tube inside the ear helps drain fluids that lead to infection.
Joint care: Affected children and adults who participate in contact sports must protect their joints. Early onset of arthritis may necessitate joint replacement surgery.
Stickler syndrome is an inherited condition and cannot be prevented. Genetic screening can help affected adults assess disease risk to their offspring. Early diagnosis and treatment is key to preventing serious complications.
“Stickler syndrome”. Mayo Clinic. Mayo Foundation for Medical Education and Research. Retrieved Aug 10, 2015. http://www.mayoclinic.org/diseases-conditions/stickler-syndrome/basics/definition/con-20027976.
“Stickler Syndrome”. Seattle Children’s Hospital. Retrieved Aug 10, 2015. http://www.seattlechildrens.org/medical-conditions/chromosomal-genetic-conditions/stickler/.
“Stickler Syndrome in Children”. Boston Children’s Hospital. Retrieved Aug 10, 2015. http://www.childrenshospital.org/conditions-and-treatments/conditions/s/stickler-syndrome/overview.