Treacher Collins Syndrome
Description
Treacher Collins Syndrome (TCS) is a rare genetic disorder that affects the development of facial structures. It can vary in severity, with some individuals experiencing mild features while others have more significant challenges. Understanding TCS, its causes, and the available management options is crucial for individuals and families affected by this condition. This blog post will delve into the essential aspects of TCS, providing information and resources for navigating this journey.
Genes Involved
Treacher Collins Syndrome is caused by mutations in specific genes that play a crucial role in facial development. The most commonly affected genes are:
- TCOF1: This gene is responsible for the production of a protein called Treacle, which is essential for craniofacial development.
- POLR1C: This gene encodes a subunit of RNA polymerase I, a key enzyme involved in ribosome biogenesis.
- POLR1D: Similar to POLR1C, this gene encodes another subunit of RNA polymerase I.
Recognizing the Signs and Symptoms
Recognizing the signs and symptoms of Treacher Collins Syndrome is vital for early diagnosis and intervention. Key features include:
- Facial Deformities: Prominent cheekbones, downward slanting eyes, small jaw (micrognathia), underdeveloped ears, cleft palate, and a wide mouth.
- Hearing Loss: TCS often affects the development of the middle ear, leading to conductive hearing loss.
- Breathing Difficulties: The small jaw and underdeveloped airway can cause breathing challenges, especially in infants.
- Eye Abnormalities: Eyelid deformities, colobomas (gaps in the eye structures), and vision problems are common.
- Dental Issues: Missing teeth, malocclusion (misalignment), and dental problems can occur.
Causes
Treacher Collins Syndrome is primarily caused by genetic mutations. In most cases, it arises due to a new mutation in the affected individual, meaning it is not inherited from their parents. However, there is a small chance that TCS can be inherited from a parent who carries a mutation in one of the involved genes.
Inheritance/recurrence risk
The inheritance pattern of Treacher Collins Syndrome is autosomal dominant. This means that if one parent carries a mutation in one of the affected genes, there is a 50% chance that their child will inherit the mutation and develop TCS. The risk of recurrence is also 50% for each subsequent pregnancy.
It‘s important to note that even if a parent carries a mutation, they may not have any signs or symptoms of TCS themselves. This is known as incomplete penetrance.
