Our Stickler's Journey: Stickler Syndrome

What is Stickler Syndrome

According to the National Organization for Rare Disorders, Stickler Syndrome is a connective tissue disorder. Connective tissue, which is the material between cells of the body that gives the tissue form and strength, is found all over the body. Connective tissue is made up of a protein known as collagen of which there are several different varieties found in the body. The specific symptoms present in Stickler syndrome often vary greatly from one individual to another. Affected individuals may not have all of the symptoms.

Stickler syndrome often affects the connective tissue of the eye, especially in the interior of the eyeball (vitreous humor), the specialized tissue that serves as a buffer or cushion for bones at joints (cartilage) and the ends of the bones that make up the joints of the body (epiphysis). It also affects the ears.

Affected individuals may also have distinctive facial features and palate abnormalities. One of the first signs in Stickler syndrome is nearsightedness (myopia), in which objects close by are seen clearly but objects that are far away appear blurry.

Myopia may vary from mild to severe in Stickler syndrome, but generally is not progressive (does not get worse). Myopia may be detectable shortly after birth, but the onset varies and may not develop until adolescence or even adulthood in some cases. Stickler syndrome is characterized by the following clinical features: vitreoretinal degeneration, myopia, cataracts, retinal holes and detachments, sensorineural hearing loss, a characteristic facial appearance with mid-facial flatness, flat nasal bridge (mid-facial hypoplasia), short button nose, small jaw (micrognathia), small chin, long upper lip (philtrum); palatal abnormalities, including cleft palate, bifid uvula or high arched palate, 30-40% of patients with Pierre Robin sequence have Stickler syndrome; musculoskeletal problems including loose joints, scoliosis, chest deformities, a hip disorder of childhood (Legg-Calve-Perthe’s disease); long fingers, early onset degenerative osteoarthritis (onset before age 40 years by X-ray); and mitral valve prolapse. An affected person does not need to have all of these features. In fact, the clinical picture is typically variable even among affected people in the same family.

Six distinct forms of Stickler syndrome have been identified in the medical literature based on the location of the mutated gene and inheritance pattern and at least one other form exists with an as yet unknown mutation location. Stickler syndrome was first described in the medical literature in 1965 by Gunnar Stickler et al., who called the disorder hereditary progressive arthro-ophthalmopathy.

Stickler syndrome types I, II, and III are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. There is a 50/50 chance of passing it on. In some cases, an affected person inherits a gene mutation from one affected parent. Other cases result from new mutations. These cases occur in people with no history of Stickler syndrome in their family.

Stickler syndrome types IV, V, and VI are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Stickler Involved People has put together a great slide show summarizing these facts: