Stickler Syndrome
Description
Stickler syndrome is a group of inherited disorders that affect connective tissues, the fibers that support and connect various parts of the body. These tissues are found in joints, bones, skin, eyes, and other organs. Stickler syndrome can cause a wide range of symptoms, depending on the severity of the condition and the specific genes involved.
Genes Involved
The genes involved in Stickler syndrome are responsible for producing proteins that play vital roles in the formation and function of connective tissues. Some of the most commonly affected genes include:
- COL2A1: This gene produces type II collagen, a major component of cartilage.
- COL11A1: This gene produces type XI collagen, another important collagen found in cartilage.
- COL9A1: This gene produces type IX collagen, which helps regulate the assembly and structure of type II collagen.
- COL1A1: This gene produces type I collagen, found in bones, skin, and tendons.
- COL1A2: This gene also produces type I collagen.
Recognizing the Signs and Symptoms
Recognizing the signs and symptoms of Stickler syndrome is crucial for early diagnosis and management. Some common features include:
- Skeletal abnormalities: Joint hypermobility (excessive flexibility), short stature, abnormal bone development, clubfoot, and scoliosis (curvature of the spine).
- Facial characteristics: Flattened midface, prominent nose, small chin, and widely spaced eyes.
- Eye problems: Myopia (nearsightedness), detached retina, glaucoma, and cataracts.
- Hearing loss: Sensorineural hearing loss, conductive hearing loss, or mixed hearing loss.
- Other symptoms: Cleft palate, heart defects, skin problems, and dental issues.
Causes
Stickler syndrome is caused by mutations in genes that code for proteins involved in the production and assembly of collagen. Collagen is a fibrous protein that provides structural support and elasticity to connective tissues. These mutations can alter the structure and function of collagen, leading to the characteristic symptoms of Stickler syndrome.
Inheritance/recurrence risk
Stickler syndrome is inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene from either parent is enough to cause the disorder. If one parent has Stickler syndrome, there is a 50% chance that their child will inherit the condition. However, the severity of the disorder can vary significantly among individuals with the same gene mutation.
