What is MPS VI?
Mucopolysarcharidosis type VI (MPS VI) is a rare, inherited disorder that is classified as a lysosomal storage disorder (LSD) in which a genetic variation disrupts the normal activity of lysosomes in human cells. MPS VI also known as Maroteaux-Lamay syndrome.
What are lysosomes and what do they do?
Lysosomes contain specific proteins (enzymes) responsible for breaking down and recycling molecules such as fats and sugars. Individuals with a lysosomal storage disorder lack one of these necessary enzymes or do not have one of these enzymes in sufficient quantities to break down molecules for proper cell function.
Mucopolysarcharidosis Type VI | Symptoms & Causes
What are the symptoms of MPS VI?
Manifestations of MPS VI fall on a broad spectrum, meaning children may or may not have symptoms. Children with MPS VI generally do not experience or display symptoms at the time of their birth. Generally, affected children begin to show signs and symptoms of the disease during early childhood.
Signs and symptoms may include:
- an enlarged head (macrocephaly)
- build-up of fluid in the brain (hydrocephalus)
- an enlarged tongue (macroglossia)
- coarse facial features
- knock-knees (genu valgum)
- umbilical hernia or inguinal hernia
- joint contractures or deformities
- short stature
Other symptoms children might experience over time include:
- sleep apnea
- hearing loss or impairment
- visual impairment/corneal clouding
- enlargement of the liver and spleen (hepatosplenomegaly)
- thickening/impairment of the heart valves
- compression of the spinal cord
- frequent respiratory infections
Unlike some forms of mucopolysarcharidosis, MPS VI does not affect intelligence.
What causes MPS VI in children?
MPS VI is caused due to a deficiency in an enzyme known as arylsulfatase-B. This condition is genetic and is inherited in an autosomal recessive pattern, which means that an affected child has received one defective copy of the gene responsible for arylsulfatase-B production from each of their parents.
Mucopolysarcharidosis Type VI | Diagnosis & Treatments
How do we treat MPS VI?
Current approaches to MPS VI are tailored to specific patients and may include enzyme replacement therapy (ERT) and targeted symptom management. Treatment plans require interdisciplinary collaboration and depend greatly on a patient’s specific disease presentation.
How we care for MPS VI
At the Boston Children’s Lysosomal Storage Disorder (BoLD) Program, our team of providers is committed to the care of complex patients. As part of Boston Children’s Hospital, we are prepared to meet the challenge of providing multifaceted care by partnering with you and your child to deliver direct care in our BoLD clinic. We work with the broad array of world-class specialists at Boston Children’s to optimize the care we provide your child with MPS VI.