Sanfilippo Syndrome Types A and B
Molecular testing
Sanfilippo syndrome is caused by a defect in one of four enzymes required for
the modification and removal of glucosamine residues from heparan sulfate. A
defect in one of these enzymes (types A-D) results in the accumulation of
heparan sulfate in the patient’s cells and organs which overtime leads to the
clinical phenotype. Sanfilippo syndrome is part of a larger group of disorders
termed the mucopolysacharidoses (MPS) of which Sanfilippo is type III.
The Greenwood Genetic Centers offers sequencing of the entire coding region of
the genes involved in Sanfilippo type A (MPS IIIA, deficiency of heparan
sulfamidase, SGSH gene) and Sanfilippo type B (MPS IIIB, deficiency of
N-acetyl-alpha-D-glucosaminidase, NAGLU gene).
Mutational analysis of either gene detects greater than 90% of the causative
mutations in enzymatically diagnosed patients. Identification of the
causative mutation/s in the proband can facilitate carrier detection in
interested family members
It is strongly recommended that the enzymatic defect be identified in the
proband before molecular testing is performed.*
Specimen requirements: 5 to 10 ml of peripheral blood collected in an EDTA (lavender
top) Vacutainer tube is preferred. The minimal blood needed for reliable
DNA isolation is 3 ml. If necessary, ACD solution A Vacutainer tubes
(yellow top) may be submitted. Please contact the laboratory for more
information.
Transport:
Please contact
Tim Wood at 1-800-473-9411 for shipping
information. The specimen should be kept at room temperature and
delivered via overnight shipping. FedEx is preferred. If shipment is
delayed by one or two days, the specimen should be refrigerated and shipped at
room temperature. Do not freeze the specimen. Samples collected on
Friday can be safely designated for Monday delivery.
Analysis standards: Analysis will be complete within 4 weeks of sample receipt.
The laboratory director assesses the quality and interpretation of results.
Technical staff members independently assess the quality and interpretation of
the test. The Greenwood Genetic Center Molecular Diagnostic Laboratory is CLIA
certified and actively participates in CAP proficiency surveys.
Reporting of Test Results: Test results with interpretation will be mailed and/or faxed
following completion of the test. Verbal reports will be telephoned to the
person(s) requesting the test when an abnormal test result occurs.
Consultation with the laboratory director and explanations of testing protocols
will be supplied upon request.
Unknown mutation:
-
CPT Codes: 83890, 83898 (x6), 83904 (x5), 83909 (x5), 83912
Known
mutation:
-
CPT
Codes:
83890, 83898, 83904 (x2), 83909, 83912
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