Congenital Disorder of Glycosylation Ib (MPI) Sequencing

Disorder Congenital Disorder of Glycosylation Ib (CDG Ib)
Gene Name MPI
Clinical info Congenital disorder of glycosylation (CDG) Ib is an autosomal recessive disorder caused by a deficiency of mannosephosphate isomerase. This enzyme normally catalyzes the conversion of mannose-6-phosphate to mannose-1-phosphate. This step is required for the addition of N-linked sugars to proteins. CDG Ib is unique among the known congenital disorders aof glycosylation by lacking significant CNS involvement. Patients may present with chronic diarrhea, failure to thrive and protein-losing enteropathy. Hepatic fibrosis may also develop. CDG Ib can be effectively treated with oral mannose supplementation.
Indications Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.
Detection Sequencing of the gene will detect over 99% of the causative mutations in patients with CDG Ib.
Associated Tests Transferrin isoelectric focusing screen
Molecular testing for CDG Ia
Molecular testing for CDG Ic
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 21 days
Prenatal testing Prenatal diagnosis is available if the familial mutations are 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: 81479

Deletion/Duplicaton Analysis: 81229
Cost $1000 for sequencing

$350 for known mutation

$700 for deletion/duplication analysis

Prenatal diagnosis for known mutation is $1000.  Please contact the laboratory 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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