What Is Stickler Syndrome?

Symptoms of Stickler syndrome can vary from one individual to another. 

The signs and symptoms of Stickler syndrome may include: 

• Distinctive facial features
  • Cleft palate
  • Small chin (micrognathia) 
  • Tongue placed further back in the mouth (glossoptosis)
    • These features together are known as Pierre-Robin sequence
    • Sometimes, these facial features may make it difficult for babies with Stickler syndrome to breathe or eat
  • Underdevelopment of the middle of the face (midface hypoplasia)
    • Abnormally flat cheek bones and nasal bridge
    • Small nose
    • Long upper lip 
    • Prominent eyes
  • Dental abnormalities such as failure of the upper and lower teeth to meet when biting down
• Eye abnormalities
  • Extreme near-sightedness (myopia)
  • Increased risk for retinal detachment 
  • Increased risk for cataracts
  • Crossed eyes (strabismus)
  • Astigmatism
  • Glaucoma, in a small number of patients
  • Some of these problems can lead to vision loss
• Ear problems
  • Hearing loss
  • Chronic (recurrent) middle ear infection 
  • Accumulation of thick, sticky fluid behind the eardrum (“glue ear”)
  • Hypermobility of the middle ear bones
• Joint problems
  • Loose joints (joint laxity) or may be very flexible (double-jointedness) that may make people prone to joint dislocation
  • Joint pain and stiffness upon rest 
  • Development of arthritis at a young age, typically before 40-years-old (early-onset osteoarthritis)
• Chest deformities such as depression of the chest bone prominent chest bone
• Spinal abnormalities
  • Scoliosis (sideways curvature of the spine)
  • Kyphosis (front-to-back curvature of the spine)
  • Flat vertebrae (platyspondyly) 
  • These problems may cause back pain 
• Osteoporosis, which can increase the risk of bone fractures
• Increased risk for mitral valve prolapse
• Diminished muscle tone
• Abnormally long, slender fingers 
• Flat feet 
• Osteochondritis deformans of the hips (Legg-Calve-Perthes disease), a degenerative hip disorder with childhood onset

Children with Stickler syndrome have normal intelligence, but some children may develop learning disabilities due to hearing and vision problems.

• Stickler syndrome is caused by genetic changes (mutations or pathogenic variants) in one of six genes: COL2A1, COL11A1, COL11A2, COL9A1, COL9A2, or COL9A3. 
• These genes are involved in providing instructions to the body to produce collagen. Mutations in any of the genes associated with Stickler syndrome cause the collagen in the body to not be produced or processed properly which results in the signs and symptoms of Stickler syndrome.

• When symptoms consistent with the Stickler syndrome such as distinctive facial features, symptoms affecting the eyes, hearing loss, joint problems, and other people in the family with similar symptoms are observed, genetic testing can be used to confirm the diagnosis.
• There is a published set of criteria to help doctors determine if a person should be diagnosed with Stickler syndrome based on signs and symptoms. 

Treatment for Stickler syndrome is aimed at treating each patient’s specific symptoms and may include: 

• Surgeries
  • Correction of cleft palate or small chin
  • Fixing retinal detachment
  • A tracheostomy to prevent breathing difficulties in patients who have Pierre-Robin sequence 
  • Myringotomy to treat “glue ear”
  • Surgical correction of joint abnormalities 
    • Joint replacement surgery 
    • Total hip or knee replacement
  • Surgery for skeletal malformations including abnormal curvature of the spine
• Preventive cryotherapy to reduce the risk of developing retinal detachment
• Corrective lenses (glasses or contact lenses) to treat vision problems
• Anti-inflammatory medications and pain medications for joint disease
• Hearing aids for hearing loss
• Patients with ocular (eye) forms of Stickler syndrome are restricted from contact sports due to the risk of retinal detachment
• Orthodonture to correct dental malalignment
• Physical therapy 
• Special education for children with learning disabilities due to hearing or vision problems
• Genetic counseling for affected individuals and their families

Early diagnosis and treatment are key to preventing many complications. Complications of Stickler syndrome may include: 

• Difficulty breathing or feeding in babies
• Increased risk for eye problems including retinal detachment and cataracts
  • Can lead to vision loss
• Development of arthritis at a young age, typically before 40-years-old (early-onset osteoarthritis)
• Hearing loss
• Mitral valve prolapse

The symptoms of Stickler syndrome are generally not life-threatening and people live a normal life span.