Testing Options for Sanfilippo syndrome
Urine MPS Analysis
Traditionally, the initial test used to screen for Sanfilippo syndrome is the “Urine MPS Analysis,” which detects if an abnormal amount of heparan sulfate is present in a child’s urine. (Of Note: This test is not part of a typical urinalysis used for determining infection.) Your physician may order a “Urine MPS Analysis” if there are concerns about Sanfilippo syndrome.
This test requires that a urine specimen be collected at home or at the medical office. It does not have to be a sterile collection. A first-of-the-morning urine sample is ideal, but not required. If the minimum of 3 mLs of urine is not collected at one time, you may combine more than one urine sample from the same day. If collected at home, the sample should be labeled, refrigerated, and taken directly to the physician or laboratory as directed.
While urine testing is still an important part of the diagnostic process, false negatives can occur. New screening methods are becoming more common as first-line tests (see below for details).
Many labs offer this test, the following is an example of one.
Genes for Sanfilippo may be tested by sampling blood, a cheek swab, or a saliva collection.
No-charge genetic testing and counseling for lysosomal storage diseases is available through Invitae. Results take an average of 10 to 21 days after Invitae receives the specimen. The preferred specimen is 3mL of whole blood.
Invitae’s test analyzes up to 53 genes, screening for 20 different lysosomal storage diseases, including Sanfilippo.
Flyer to take to your doctor. Download informational flier to share with your doctor.
A blood enzyme assay is considered the most-credible diagnostic tool in testing for Sanfilippo Syndrome because it detects whether or not one of the enzymes in the cellular pathway that breaks down heparan sulfate is missing (the functional cause of Sanfilippo Syndrome), providing a definitive answer.
Because of its accuracy, this test is often used to confirm the findings of a positive urine screen.
This test requires a blood draw. Usually from the arm.
This blood enzyme test is ideal for younger patients with whom collecting a viable urine sample for the Urine MPS Screening is difficult or impossible.
Physicians can order a full enzyme assay blood test for Sanfilippo Syndrome, free of charge for eligible patients from BioMarin Pharmceutical Inc., at WhatWouldYouSuspect.com.
Sanfilippo Syndrome is currently not included on any state’s newborn screening public health program. However, supplemental screening services are available that you can order.
Private Newborn Screening
Eli by Baebies is an expanded newborn screening service that provides additional screening for children up to age 1 for conditions that are not part of standard state screening, including testing for Sanfilippo Syndrome, Types A & B (MPS III A & B).
Eli makes it simple:
1). Order your kit online at eliscreen.com;
2). Bring the kit to your healthcare provider and they will collect the needed samples from your newborn; and
3). Ship the samples to Baebies’ lab and you will receive your results within seven days.
The Invitae Mucopolysaccharidosis Type III Panel analyzes a patients genetics for the known genes/mutations associated with Sanfilippo Syndrome.
This test is useful for the diagnosis of patients in whom Sanfilippo is suspected due to clinical symptoms or elevated urinary glycosaminoglycans (GAGs).
There could be instances where a child has a never-before-seen genetic mutation that causes Sanfilippo Syndrome. Because it isn’t a known gene mutation, it would result in a false negative with this test.
Face2Gene is a suite of phenotyping applications that facilitate comprehensive and precise genetic evaluations.
The Face2Gene Clinic app detects phenotypes of more than 7,500 genetic disorders, including Sanfilippo Syndrome, from facial photos a practitioner uploads, automatically calculates anthropometric growth charts, and suggests likely phenotypic traits to assist in feature annotation.
A clinician can review relevant syndrome phenotypes matches to genetic disorders based on gestalt and refine relevance of genetic disorders based on deep phenotyping.
Review the phenotypic traits of Sanfilippo Syndrome.