Medical Genetics

Glycogen Storage Disease Type 1A Carrier Testing

Glycogen storage disease type 1A is characterized by an accumulation of glycogen and fat in the liver and kidneys. The disease is an autosomal recessive disorder which is caused by mutations in the G6PC gene and subsequent deficiency of the enzyme glucose-6-phosphatase. The carrier risk for glycogen storage disease type 1A in the Ashkenazi Jewish population is 1 in 71.

Glycogen storage disease type 1A carrier testing by DNA analysis is offered as part of a genetic screening panel for the Ashkenazi Jewish population which includes mucolipidosis IV, Niemann-Pick disease type A, and Bloom syndrome. See Ashkenazi Jewish Genetic Screening - Panel 2 for testing information.

Indications for Testing

Carrier screening

Gamete donors

Testing Methodology

Direct mutation analysis: Our laboratory utilizes Amplification Refractory Mutation System (ARMS) technology to screen for a single mutation relevant to the Ashkenazi Jewish population. The single mutation is R83C.

Sensitivity

The carrier detection rate for DNA analysis of glycogen storage disease type 1A in the Ashkenazi Jewish population is 97%.

This carrier screening test is most appropriate for individuals of Ashkenazi Jewish descent. This test may not be appropriate for individuals from other ethnic backgrounds. The sensitivity of this carrier screen in non-Jewish populations has not been established. This test is not appropriate for fetal diagnosis or diagnosis of individuals with clinical phenotype.

Specimen Requirements

Blood: 5 cc whole blood collected in a purple top (EDTA) or yellow top (acid citrate dextrose) vacutainer tube. Do not centrifuge or freeze. Sample may be refrigerated or stored at room temperature.