Stickler syndrome: A relatively common genetic disorder characterized by very flexible (hyperextensible) joints, typical facial characteristics, hearing loss, and severe nearsightedness with associated eye problems. The typical facial features include flattened bridge of the nose and flat cheekbones. A particular group of physical features, called the Robin sequence (or Pierre Robin sequence), is also common in children with Stickler syndrome. Robin sequence includes a U-shaped cleft palate with a tongue that is too large for the space formed by the small lower jaw. Children with a cleft palate are also prone to frequent ear infections and swallowing difficulties.
The eye findings may include changes in the jelly-like substance inside the eyes (the vitreous) and increased risk of glaucoma, retinal detachment, and cataracts. Hearing loss can involve both the middle ear and inner ear. (This form of hearing loss is called mixed conductive and sensorineural hearing loss because it involves bone movement in the middle ear and sensory nerve cells in the inner ear.) Young people with Stickler syndrome may have extremely flexible joints, which become less flexible with time. People with the syndrome may develop arthritis-like symptoms as adults along with progressive spine problems and back pain.
Treatment is directed at the specific problems and may include the repair of a cleft palate, speech therapy, hearing instruments, laser surgery for retinal detachment, joint surgery for the arthritis, and walking aids. Genetic counseling is recommended since Stickler syndrome is inherited in an autosomal dominant manner, heritable by both males and females in multiple generations. Some cases in which there is no family history of the disease are due to a new mutation.
Stickler syndrome is not one disease. It is genetically heterogeneous. All of the known types of Stickler syndrome are due to mutations in the genes for collagen, a fibrous protein that is a key component of connective tissue. There are multiple types of Stickler syndrome, each due to mutation in a different gene:
- One form of Stickler syndrome is due to mutation in the COL2A1 gene on chromosome 12 in region 12q13.11-q13.2. It is termed Stickler syndrome, type I and symbolized STL1. (It is alternatively known as Vitreous type Stickler syndrome; Membranous vitreous type Stickler syndrome; and Hereditary progressive arthroophthalmopathy or AOM.)
- A second form of Stickler syndrome is caused by mutation in the COL11A1 gene on chromosome 1 in region 1p21. It is termed Stickler syndrome, type II and symbolized STL2. (It is alternatively known as Vitreous type 2 Stickler syndrome; and Beaded vitreous type Stickler syndrome.)
- A third form of Stickler syndrome is caused by mutation in the COL11A2 gene on chromosome 6 in region 6p21.3. It is termed Stickler syndrome, type III and symbolized STL3. The eyes are normal in this type of the syndrome. (It is alternatively known as Nonocular type Stickler syndrome).
There is evidence for the existence of at least one additional form of Stickler syndrome.
The syndrome is named for the German-American pediatrician Gunnar B. Stickler (1925-).