PMM2-congenital disorder of glycosylation (PMM2-CDG, also known as congenital disorder of glycosylation type Ia) is an autosomal recessive disorder and is the most common form of congenital disorders of glycosylation (CDG) disorders. It presents with a broad and highly variable range of symptoms and severity, ranging from mild cases to severe, disabling or life-threatening cases. Most cases are apparent in infancy.
PMM2-CDG is caused by homozygous or compound heterozygous mutation in the PMM2 gene of chromosome 16 (16p13) encoding the phosphomannomutase-2 (PMM2) enzyme. Mutations in the gene lead to the production of an abnormal PMM2 enzyme with reduced activity. Without a functioning enzyme, glycosylation cannot proceed normally. As a result, incorrect oligosaccharides are produced and attached to proteins. The wide variety of signs and symptoms in PMM2-CDG are likely due to the production of abnormally glycosylated proteins in many organs and tissues.
The diagnosis of PMM2-CDG is typically established with a combination of carbohydrate-deficient transferring analysis and identifying pathogenic variants in the PMM2 gene.
Genetics - Molecular Pathology
Patient specimen - EDTA, extracted DNA, buccal swab, saliva
This genetic test requires nucleated cells. Please do not centrifuge or freeze the EDTA blood tube.
Ambient (8 - 24 degrees Celsius)
Please do not centrifuge or freeze the EDTA blood tube.
Coding regions and flanking intronic sequences of all 8 exons of the PMM2 gene are amplified by PCR and analysed by automated fluorescent bi-directional DNA sequencing.
$700.00 (Exclusive of GST)
Genomic DNA must be extracted from the specimen prior to testing. This incurs an additional charge (see GDNA). Laboratories may prefer to submit DNA for testing. Please provide a minimum of 5 micrograms of DNA at 20 nanograms/microlitre.