Sanfilippo Syndrome: Causes, Symptoms, Treatment

Author: Thomas C. Weiss
Published: 2010/02/24 - Updated: 2023/02/01
Peer-Reviewed: N/A
Contents: Summary - Main - Related Publications

Synopsis: Sanfilippo syndrome is a form of inherited disease involving metabolism. The condition makes the body unable to break down long chains of sugar molecules appropriately . There are four main types of Sanfilippo syndrome, also referred to as MPS III. The type of the syndrome a person has depends upon which enzyme is affected. Sanfilippo syndrome is inherited as an autosomal recessive trait. This means that both of the parents of the person affected by the disease have passed them the defective gene.

Main Digest

Defining Sanfilippo Syndrome

Sanfilippo syndrome is a form of inherited disease involving a person's metabolism. The disease makes a person's body unable to appropriately break down long chains of sugar molecules referred to as, 'glycosaminoglycans.' The syndrome is one of a group of diseases known as 'mucopolysaccharidoses,' or MPS. Sanfilippo syndrome is also known as MPS III.

The U.S. Social Security Administration (SSA) has included Sanfilippo Syndrome as a Compassionate Allowance to expedite a disability claim.

Sanfilippo syndrome tends to be fatal before the age of twenty years, although there are a few exceptions, and it is currently not a disease that is curable. A diagnosis of the disease is usually reached within the first few years of a person's life when a child does not develop as they might be expected to, or they start to experience losses in developmental achievements.

Causes of Sanfilippo Syndrome

Sanfilippo syndrome occurs when the enzymes needed to break down the heparan sulfate sugar chain are either defective or missing entirely. There are four main types of Sanfilippo syndrome, also referred to as MPS III. The type of the syndrome a person has is dependent upon which enzyme is affected.

Sanfilippo syndrome is inherited as an autosomal recessive trait. This means that both parents of the person affected by the disease have passed them the defective gene.

Symptoms of Sanfilippo Syndrome

There is usually no way for parents to determine that their child has been born with Sanfilippo syndrome that is present - unless the disease has been suspected and the parents have pursued genetic testing. Some children with the syndrome present with a larger head than average, although many children seem to be just fine. After their first year of life, children with Sanfilippo syndrome can experience symptoms that may become more evident. These symptoms may include chronic diarrhea, agitation, poor behavior, and failure to make developmental gains. Some children with the syndrome can also experience seizures, stiffness in their legs, and joint problems. They may develop confusion or dementia and be prone to respiratory infections.

Some children with Sanfilippo syndrome have characteristic appearance markers that may suggest the disease, such as a larger head. Others might have more adult-looking facial features, fuller lips, or heavy eyebrows that could be thick and meet in the middle. Their hair might also be courser or more profuse in its growth than could usually be expected in a child.

Children with Sanfilippo syndrome usually experience a decline in their ability to learn between the ages of two and six years. They might experience an average growth rate for their first few years of life, but their final height is commonly below average. A deterioration usually follows developmental delays experienced by children with Sanfilippo syndrome in their mental status.

Symptoms of Sanfilippo syndrome can include:

Diagnosing Sanfilippo Syndrome

Sanfilippo syndrome is usually identified as an inherited disorder. While the parents of a child with the syndrome do not have the syndrome themselves, they each have a recessive gene for it. The gene is passed to their child, which is referred to as an 'autosomal recessive inheritance pattern.' People who are aware that someone in their family has, or has had, Sanfilippo syndrome - including cousins, aunts, or uncles, should consider receiving testing with their partner before conceiving a child. Both parents must have the gene for Sanfilippo syndrome to pass the syndrome to a child. Even if one parent has it, it should be noted that the next generation of children needs to be aware that they might carry the recessive gene.

The degree to which Sanfilippo syndrome progresses can be determined by the type of syndrome involved. There are four types of Sanfilippo syndrome, labeled A through D. Each one of the types represents a lack of a particular enzyme that makes it difficult for the affected person to break down long-chain sugars. The type of Sanfilippo syndrome a person has could, in part, determine the outcome. Sanfilippo syndrome type A is many times considered to be both the most common type of the syndrome, as well as the most severe.

A physical examination can demonstrate spleen or liver swelling in a person with Sanfilippo syndrome. Eye examination shows clear corneas in persons with the syndrome. Neurological testing of people with the syndrome reveals signs of mental retardation and seizures. Urine testing can also be performed, and people with Sanfilippo syndrome have large amounts of mucopolysaccharide, referred to as 'heparan sulfate,' in their urine. Additional testing related to Sanfilippo syndrome can include:

Treatment of Sanfilippo Syndrome

There is currently no cure for Sanfilippo syndrome. People with the syndrome and their family members find that support from physical therapists, occupational therapists, and doctors can be vital. Forms of medical treatments can help to ease some of the conditions associated with the syndrome, although they will not fully alter the course of the disease itself. Caregivers will also need support, and other children in the family who do not have the disease might benefit from counseling and support. Behavioral issues can be problematic for the entire family, and the prospect of losing a sibling is particularly troubling.

The best possible treatment would be a way to cure the illness, of course, but a cure remains elusive. Because medical science has not discovered a cure, children diagnosed with Sanfilippo syndrome often live short lives. New treatments in gene and stem cell therapies that are in development could mean that someday Sanfilippo syndrome will become a treatable condition.

Complications of Sanfilippo syndrome can include blindness, mental retardation, nerve damage that slowly worsens and eventually requires wheelchair use, and seizure activity. People affected by the syndrome can have I.Q.s below 50. Many people with Sanfilippo syndrome live into their teenage years, although some live longer. Others die at a younger age.

Author Credentials:

Thomas C. Weiss is a researcher and editor for Disabled World. Thomas attended college and university courses earning a Masters, Bachelors and two Associate degrees, as well as pursing Disability Studies. As a Nursing Assistant Thomas has assisted people from a variety of racial, religious, gender, class, and age groups by providing care for people with all forms of disabilities from Multiple Sclerosis to Parkinson's; para and quadriplegia to Spina Bifida. Explore Thomas' complete biography for comprehensive insights into his background, expertise, and accomplishments.

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Cite This Page (APA): Thomas C. Weiss. (2010, February 24). Sanfilippo Syndrome: Causes, Symptoms, Treatment. Disabled World. Retrieved February 27, 2024 from

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