Glycogen Storage Disease, Type 1A (G6PC), 9 Variants
Also known as: G6PC
Use
The Glycogen Storage Disease, Type 1A (G6PC), 9 Variants test is performed for carrier screening or diagnostic testing for glycogen storage disease type 1A, specifically for individuals of Ashkenazi Jewish descent. This test evaluates nine specific pathogenic variants in the G6PC gene, which are responsible for Type 1A Glycogen Storage Disease. Infants with this condition typically present symptoms at 3 to 4 months of age, including hepatomegaly, lactic acidosis, hyperuricemia, hyperlipidemia, hypertriglyceridemia, and hypoglycemic seizures. Additional characteristics of the disease include growth delay leading to short stature, osteoporosis, delayed puberty, renal disease, and hepatic adenomas with potential for malignancy. However, with proper treatment, individuals affected often live into adulthood.
Special Instructions
Counseling and informed consent are recommended for genetic testing, particularly for patients from New York due to state-specific regulations. Informed Consent for Genetic Testing is required and available online. Variants outside of those tested will not be detected, and diagnostic errors can occur due to rare sequence variations. It is important to consider that this test is intended as a carrier screening or diagnostic testing tool for glycogen storage disease type 1A, primarily for those of Ashkenazi Jewish descent.
Limitations
This test has certain limitations, including the inability to detect variants other than those specified, which are p.Q27Rfs, Y128Tfs, p.R83H, p.R83C, p.G188R, p.Q242X, p.Q347X, p.G270V, and p.F327del. Diagnostic errors may occur due to rare sequence variations, and while the analytical sensitivity and specificity are both greater than 99%, these figures might vary in non-Ashkenazi Jewish individuals.
New York Approved
Methodology
PCR-based (qPCR)
Biomarkers
Result Turnaround Time
5-10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B)
Storage Instructions
Refrigerated.
Causes for Rejection
Plasma or serum, specimens collected in sodium heparin or lithium heparin tubes, frozen specimens in glass collection tubes.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 1 week |
| Frozen | 1 month |
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