Sanfilippo Syndrome, also known as Mucopolysaccharidosis III (MPS III), is a rare genetic disorder that affects the metabolism of certain sugars in the body. This disorder leads to a build-up of these sugars in various organs and tissues, causing progressive damage and multiple symptoms. Sanfilippo Syndrome is a serious condition that can cause significant developmental delays, cognitive impairment, childhood dementia, and physical abnormalities.
In this article, experts at the Pediatric Endocrine and Metabolic Center of Florida will explore the causes, symptoms, and treatment options for Sanfilippo Syndrome and current support options for affected individuals and families.
What Causes Sanfilippo Syndrome?
Sanfilippo Syndrome is caused by mutations in the genes responsible for producing specific enzymes needed to break down complex sugars called heparan sulfate. These enzymes are necessary for the normal metabolism of these sugars, and their build-up in the body causes the symptoms of Sanfilippo disease.
There are four types of Sanfilippo Syndrome, each caused by a different gene mutation:
- Type A is caused by a mutation in the SGSH gene.
- Type B is caused by a mutation in the NAGLU gene.
- Type C is caused by a mutation in the HGSNAT gene.
- Type D is caused by a mutation in the GNS gene.
The disorder is inherited in an autosomal recessive pattern, meaning a child has to inherit two copies of the mutated gene (one from each parent) to develop the condition. If a person inherits only one copy of the mutated gene, they will be a carrier of the disorder but will not develop symptoms.
It is a rare disorder, with an estimated incidence of 1 in 70,000 live births. It occurs in all ethnic groups, and both males and females are affected equally. The disorder is usually diagnosed in early childhood and can lead to severe cognitive and physical developmental problems.
The Signs and Symptoms of Sanfilippo Syndrome
The signs and symptoms of Sanfilippo disease can vary depending on the type of the disorder and the severity of the gene mutation. However, some common symptoms are seen in all types of the disorder.
Children with Sanfilippo Syndrome may struggle with memory, attention, and problem-solving skills. They may display aggression, self-injurious behavior, and sleep disturbances. In the early stages of the disorder, affected children may have delayed developmental milestones such as delayed speech and language development, difficulty with fine motor skills, and hyperactivity. As the disorder progresses, cognitive impairment, behavioral problems, and childhood dementia may become more pronounced.
The physical symptoms of Sanfilippo disease include coarse facial features, enlarged liver and spleen, joint stiffness, and skeletal deformities. Children with the disorder may also experience recurrent infections, hearing loss, and vision problems.
In type A and type B, symptoms usually appear between the ages of two and six, while type C and type D symptoms usually appear between the ages of four and eight. As the disorder progresses, affected individuals may experience a decline in their overall health and develop complications such as respiratory infections, sleep apnea, and heart problems.
It is important to note that the symptoms and progression of the disorder can vary widely among affected individuals, even among those with the same type of disease. Early diagnosis and Sanfilippo Syndrome treatment are crucial to managing the symptoms and complications of the disorder.
How Is Sanfilippo Syndrome Diagnosed?
Sanfilippo Syndrome is a rare genetic disorder, and diagnosis can be challenging. A combination of tests is usually used to diagnose the disorder, including:
- Physical examination: Your doctor will perform a physical examination to look for common physical characteristics of Sanfilippo Syndrome, such as coarse facial features, joint stiffness, and skeletal deformities.
- Blood tests: Blood tests will be performed to measure the levels of specific enzymes that break down complex sugars called heparan sulfate. Low levels of these enzymes can indicate Sanfilippo Syndrome.
- Genetic testing: Genetic testing can confirm the diagnosis of Sanfilippo Syndrome by identifying the specific gene mutation responsible for the disorder. This test is usually done after a positive result from a blood test.
- Imaging studies: Imaging studies such as X-rays, CT scans, or MRI may be performed to look for signs of organ damage or other disorder complications.
- Developmental assessments: Developmental assessments such as cognitive, speech, and language checks may be performed to evaluate the child’s developmental milestones and cognitive function.
It is important to note that the symptoms of Sanfilippo Syndrome can be similar to those of other conditions, so a combination of tests is usually needed to confirm a diagnosis. A genetic counselor can help families understand the results and implications of genetic testing. An early diagnosis also allows families to plan for the future and access support services.
Sanfilippo Syndrome Treatment Options
There is currently no cure for this disorder, and Sanfilippo Syndrome treatment options are primarily focused on managing its symptoms and complications. That said, treatment options may include the following:
- Enzyme replacement therapy: This therapy is currently available for types A and B of Sanfilippo Syndrome. The therapy involves administering the missing enzyme to the patient through regular infusions to help break down the excess sugar in the body.
- Gene therapy: This is an experimental treatment option for Sanfilippo Syndrome that aims to replace the missing or defective gene responsible for the disorder. Research is ongoing, and clinical trials have begun for type A of Sanfilippo Syndrome.
- Symptomatic treatment: Treatment options for managing the symptoms of the disorder may include medication to control hyperactivity and aggression, physical therapy to improve joint function and mobility, speech therapy to improve communication skills, and occupational therapy to improve fine motor skills.
- Hospice and palliative care: As the disorder progresses, patients may require specialized care in their final stages of life. Hospice and palliative care can help manage symptoms and support patients and their families.
- Supportive care: Supportive care is an essential aspect of managing Sanfilippo Syndrome. This may include counseling and support groups for families and respite care to provide relief for caregivers.
It’s important to note that treatment options for Sanfilippo Syndrome are limited and may not be available in all countries. Also, it is crucial to work with a team of specialists, including a pediatrician, neurologist, genetic counselor, and other healthcare professionals, to determine the best course of treatment for the individual patient.
Seek Expert Medical Help
The term “pediatric genetic disorders” refers to a wide range of problems that can arise from chromosomal abnormalities in children. Many different medical issues can develop due to a genetic condition, whether passed down through generations or formed by chance. Early diagnosis and treatment for genetic disorders can enhance your children’s quality of life. If you have any worries about your child’s health, don’t hesitate to reach out to us at the Pediatric Endocrine and Metabolic Center of Florida.