Glycogen Storage Disease Type Ia

Test Description:
Glycogen Storage Disease Type Ia (GSD Ia) is an autosomal recessive metabolic disorder that is caused by deficiency of microsomal glucose-6 phosphatase (G6Pase) activity, which catalyzes the final step of glycolysis. This results in severe hypoglycemia, hepatomegaly, growth retardation and a bleeding diathesis. In addition, lactic acidemia, hyperlipidemia and hyperuricemia in patients lead to long-term complications that include hepatic adenomas, osteoporosis and progressive renal disease. The estimated worldwide frequency of GSD Ia is 1:100,000, but the carrier frequency in the Ashkenazi Jewish population is estimated to be 1 in 64. Based on the data reported from American Ashkenazi Jewish GSD Ia patients, screening for p.R83C and p.Q347X in the G6PC gene is expected to identify greater than 95% of carriers in this population. Carrier screening for GSDIa may be considered for individuals of Eastern European (Ashkenazi) Jewish ancestry before/during pregnancy.

References:
1. Lei K. et al., (1993) Mutations in the glucose-6-phosphatase gene that cause glycogen storage disease 1a. Science 262:580-583.
2. Lei K. et al., (1995) Genetic basis of glycogen storage disease Ia: prevalent mutations at the glucose-6-phosphatase locus. Am J Hum Gen 57:766-771.
3. Ekstein J. et al., (2004) Mutation frequencies for glycogen storage disease Ia in the ashkenazi jewish population Am J Med Gen 129A:162-164.
4. Scott, S.A., Edelmann, L., Liu, L., Luo, M., Desnick, R.J. and Kornreich, R. Experience with carrier screening and prenatal diagnosis for sixteen Ashkenazi Jewish Genetic Diseases. Hum. Mutat. 31:1-11, 2010.

Specimen Requirements:
Two 5-10 ml tubes of anticoagulated blood. The preferred anticoagulant is EDTA (lavendar top tubes), ACD (yellow top) tubes are also accepted.

Shipping: Send at room temperature.

Turnaround Time: 10-14 days

CPT Codes: 83891, 83892x2, 83900, 83912, 83914x2

Consent and Requisition Forms: Carrier Screening Requisition and Consent [PDF]

Additional Information: Jewish Genetic Screening Brochure [PDF]

Related Tests: Ashkenazi Jewish Carrier Test Panel

Prior to ordering prenatal testing, please contact our laboratory at 212-241-7518 to discuss.