Morquio B, MPS IVB (GLB1) Sequencing

Disorder Morquio syndrome type B, MPS IVB
Gene Name GLB1
Clinical info

Morquio syndrome, or mucopolysaccharidosis, type IV, is characterized by short stature and trunk, large head, mildly coarse facies, widely spaced teeth, corneal clouding, a bell-shaped chest, genu valgum, vertebral anomalies, joint stiffness and kyphoscoliosis. Other features may include inguinal hernia, hepatomegaly and hearing loss. There is a wide clinical spectrum of those affected ranging from mild to severe.

Intelligence is typically not affected. Morquio type B is usually clinically indistinguishable from Morquio type A. These are autosomal recessive conditions.

Indications Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutation within a family to allow for carrier testing and prenatal diagnosis.
Associated Tests

Urine mucopolysaccharide analysis is available in the Biochemical Diagnostic Lab and may be useful for screening for this disorder. Enzyme testing for beta-galactosidase activity is also available and can be used to help establish the diagnosis.

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.
Transport 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.
Turnaround time 3 weeks
Prenatal testing Prenatal diagnosis is available if the familial mutation is known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.
CPT Codes Unknown mutation: 81479

Known mutation: 81404

Deletion/Duplication Analysis: 81229
Cost

$1200 for full sequencing (unknown mutation)

$350 for known mutation

$700 for deletion/duplication analysis

Prenatal diagnosis for a known mutation is $1000.  Please contact the lab for more information.

Contact For further information contact This email address is being protected from spambots. You need JavaScript enabled to view it. , MS, Lab Counselor at 1-800-473-9411.

Molecular Diagnostic Lab

The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.

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