Usher Syndrome Type 1
Description
Usher Syndrome Type 1 is a rare genetic disorder that affects both hearing and vision. Individuals with Usher Syndrome Type 1 experience progressive hearing loss from birth or early childhood and develop retinitis pigmentosa (RP), a degenerative eye condition, later in life. This comprehensive guide provides information about the signs, causes, diagnosis, management, and ways to thrive with Usher Syndrome Type 1.
Genes Involved
Usher Syndrome Type 1 is caused by mutations in one of several genes, including:
- MYO7A: This gene provides instructions for making a protein called myosin VIIA, crucial for the function of hair cells in the inner ear and the photoreceptor cells in the retina.
- USH1C: This gene is involved in the production of a protein that helps connect the hair cells in the inner ear to other cells.
Recognizing the Signs and Symptoms
Recognizing the Signs and Symptoms of Usher Syndrome Type 1 can be crucial for early diagnosis and intervention. Common symptoms include:
- Hearing Loss: Present from birth or early childhood, usually profound or severe. This can lead to difficulties with speech development and understanding language.
- Retinitis Pigmentosa (RP): Typically develops in adolescence or early adulthood. RP causes a gradual loss of night vision and peripheral vision, leading to tunnel vision and, eventually, blindness.
- Balance Issues: Some individuals with Usher Syndrome Type 1 may experience balance problems due to the involvement of the inner ear.
- Other Symptoms: A small percentage of individuals may exhibit additional symptoms, such as kidney problems or heart defects.
Causes
Usher Syndrome Type 1 is an inherited disorder, meaning it is passed down from parents to their children. The disorder is caused by a mutation in one of the genes responsible for hearing and vision development. If one parent carries the mutated gene, there is a 50% chance that their child will inherit the condition. If both parents carry the mutated gene, there is a 75% chance that their child will inherit the condition.
Inheritance/recurrence risk
Usher Syndrome Type 1 is inherited in an autosomal recessive pattern. This means that an individual must inherit two copies of the mutated gene, one from each parent, to develop the disorder. If both parents are carriers of the mutated gene, there is a 25% chance that each child will inherit the disorder. However, if only one parent carries the mutated gene, there is a 50% chance that their child will become a carrier of the condition.
