Summary about Disease
Brown-Vialetto-Van Laere syndrome (BVVLS) is a rare, progressive neurological disorder characterized by progressive sensorineural hearing loss, bulbar palsy (affecting speech, swallowing, and facial movements), and respiratory difficulties. It primarily affects children and young adults, although onset can occur at any age. BVVLS is caused by mutations in genes responsible for riboflavin transport.
Symptoms
Progressive sensorineural hearing loss (often the first symptom)
Bulbar palsy:
Difficulty speaking (dysarthria)
Difficulty swallowing (dysphagia)
Facial weakness
Tongue atrophy
Respiratory problems:
Respiratory insufficiency
Sleep apnea
Muscle weakness (progressive)
Sensory loss
Optic atrophy (in some cases)
Other neurological symptoms like ataxia (loss of coordination).
Causes
BVVLS is caused by mutations in the SLC52A2 or *SLC52A3* genes. These genes provide instructions for making proteins that transport riboflavin (vitamin B2) into cells. Mutations in these genes impair riboflavin transport, leading to a deficiency of riboflavin in certain cells, particularly nerve cells, which disrupts their function and leads to the symptoms of BVVLS. It is inherited in an autosomal recessive manner.
Medicine Used
The primary treatment for BVVLS involves high doses of oral riboflavin (vitamin B2). Early diagnosis and treatment with riboflavin can slow or halt the progression of the disease in some individuals. Other treatments are supportive, focusing on managing specific symptoms and complications. This may include:
Hearing aids or cochlear implants for hearing loss.
Speech therapy for dysarthria.
Nutritional support for dysphagia.
Respiratory support (e.g., mechanical ventilation) for respiratory insufficiency.
Physical therapy to maintain muscle strength and mobility.
Is Communicable
No, Brown-Vialetto-Van Laere syndrome is not communicable. It is a genetic disorder caused by gene mutations and cannot be spread from person to person.
Precautions
Since BVVLS is a genetic disorder, there are no specific precautions to prevent its occurrence in individuals. For families with a history of BVVLS, genetic counseling and testing can help determine the risk of having a child with the condition. Precautions for individuals with BVVLS focus on managing symptoms and preventing complications:
Regular monitoring of hearing, speech, swallowing, and respiratory function.
Adherence to riboflavin therapy.
Prevention of respiratory infections.
Adaptive strategies for communication and feeding difficulties.
How long does an outbreak last?
BVVLS is not an infectious disease, so there are no "outbreaks". It is a chronic, progressive genetic disorder. The symptoms persist throughout the individual's life, although the rate of progression can vary. With riboflavin treatment, the progression can be slowed or stabilized in some patients.
How is it diagnosed?
Diagnosis of BVVLS typically involves:
Clinical evaluation: Assessment of symptoms, including hearing loss, bulbar palsy, and respiratory difficulties.
Hearing tests (audiometry): To confirm sensorineural hearing loss.
Neurological examination: To assess motor and sensory function.
Magnetic resonance imaging (MRI) of the brain and spinal cord: To look for characteristic abnormalities.
Genetic testing: To identify mutations in the SLC52A2 or *SLC52A3* genes.
Riboflavin transporter assay: to test for impaired riboflavin transport in fibroblasts.
Timeline of Symptoms
The timeline of symptoms can vary, but generally:
Early childhood: Hearing loss is often the first symptom to appear.
Childhood/Adolescence: Bulbar palsy (speech and swallowing difficulties), and progressive muscle weakness often develop.
Variable: Respiratory problems may develop at any stage.
Progression: Symptoms typically worsen over time if untreated. Early diagnosis and riboflavin treatment can influence the disease course.
Important Considerations
Early diagnosis and treatment are crucial for improving outcomes.
BVVLS is a complex condition that requires a multidisciplinary approach to care, involving neurologists, audiologists, speech therapists, respiratory therapists, and other specialists.
Genetic counseling is important for families with a history of BVVLS.
Research is ongoing to better understand the disease and develop new treatments.
Support groups and patient advocacy organizations can provide valuable resources for individuals and families affected by BVVLS.