Heart Problems and Sanfilippo

Brian Murphy, Ph.D. avatar

by Brian Murphy, Ph.D. |

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Sanfilippo syndrome, or mucopolysaccharidosis type III (MPS III), is a rare disease that belongs to a group of disorders involving the breakdown of long sugar molecules called mucopolysaccharides or glycosaminoglycans (GAGs). Heart problems are common in most of these disorders but are generally milder and rarer in Sanfilippo syndrome. It is, however, still important to be aware of the potential of cardiac issues in Sanfilippo syndrome patients, especially as the disease progresses.

What types of heart problems might patients have?

Several different heart conditions may be present in patients with Sanfilippo syndrome.

A study in 26 patients, ages 1 to 27, found that 10 (38%) had heart valve problems. Of those, four (15%) had a narrowing of the valves, and eight (31%) had valves that leaked. Valve problems were more common in older patients. Five patients had additional thickness in the wall between the lower chambers of the heart, called the ventricles. Eleven patients had arrhythmias (irregular heartbeats).

Another study in 25 children with Sanfilippo syndrome found similar results with valve problems being the most common issues and some patients having increased thickness in the walls of the left ventricle. The left ventricle is the large chamber at the bottom of the heart that pumps blood to the rest of the body.

How does Sanfilippo cause heart problems?

In mucopolysaccharidoses, gene mutations lead to a lack of enzymes that break down GAGs. Without enough enzymes, the GAGs accumulate in different tissues and lead to problems.

In Sanfilippo syndrome, mutations lead to a buildup of a particular GAG called heparan sulfate. Heparan sulfate can accumulate in the valves, muscles, and blood vessels of the heart, leading to stiffness and interfering with normal function.

How do doctors diagnose heart problems?

Doctors usually diagnose problems with the structure and function of the heart through an echocardiogram. They place a device on the chest that emits sound waves. The sound waves then bounce off the heart tissue, and are picked up by a receiver. The way in which the sound waves bounce back can show the structure and movement of blood. An echocardiogram can show blood flow and any abnormalities in the size and movement of the heart muscles and valves.

To investigate problems with the electrical activity of the heart, such as arrhythmias, doctors use an electrocardiogram (ECG or EKG). In this method, they place electrodes on the chest and record the electrical activity of the heart muscles to look for irregular patterns.

What are the treatment options?

Severe cardiac problems are rare in patients with Sanfilippo syndrome. Most cases are mild and do not require any treatment.

In more severe cases, doctors may prescribe medications such as blood thinners to help prevent the formation of blood clots.

In cases of extreme valve problems, valve surgery may be necessary.


Last updated: Feb. 8, 2021


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