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Test Code POMPE KNWN Pompe Known Mutation

Clinical System Name

Pompe Known Mutation Analysis

Synonyms

 

Acid Alpha-Glucosidase Deficiency

Acid Maltase Deficiency

GAA Deficiency

GSD II

Glycogenosis Type II

Description

This test involves targeted analysis for mutations previously identified through clinical testing of a family member or  research testing of the individual.  It can be used for carrier testing for at-risk relatives and prenatal testing for confirmed carriers. Mutations must be known. For full gene sequencing please see Pompe DNA Sequencing.

 

Individuals with Pompe disease are unable to use the glycogen stored in the lysosomes for energy, resulting in the progressive storage of glycogen in the heart, liver, and skeletal muscle. Pompe disease can present in infancy with profound hypotonia, cardiomegaly and cardiomyopathy or later in childhood and adulthood with progressive muscle weakness and respiratory insufficiency. Pompe disease is caused by mutations in the GAA gene.

Sample Requirements

Specimen: Whole blood, cord blood

Container(s): Lavender/EDTA, Yellow/ACD A or B

Preferred Vol: 3 mL

Minimum Vol: 1 mL

 

Note: Heparin samples (Green tops) are unacceptable.

 

Specimen: Extracted DNA

Minimum: 10µg

Note: DNA concentration minimum 50 µg/mL; 260/280 ratio 1.70-2.00

  

Specimen: Cultured cells

Acceptable:  Fibroblasts

Container(s): T-25 flasks

Preferred Vol: 2 flasks

Processing Instructions

Reject due to: Heparin

Spin: No

Aliquot: No

Temp: Refrigerate

Storage location: Molecular Genetics box in CPA refrigerator #2

 

Off-site collection: Refrigerate blood samples until ready to ship.  Transport all sample types at room temperature via overnight shipping.

Stability

Specimen Type Temperature Time
Cultured cells Room temp 3 days
Whole blood, extracted DNA Room temp 3-5 days
Whole blood, extracted DNA Refrigerated 7 days
Extracted DNA Frozen ok

 

Note: Whole blood samples > 7days may be submitted to be assessed by our lab for acceptability for testing.

Availability

STAT Performed TAT
Contact lab Monday - Friday 2-3 weeks

 

Performing Laboratory

Seattle Children's Laboratory

Department

Department:  Molecular Genetics Laboratory

Phone: 206-987-3872

 

Lab Client Services: 206-987-2617

 

Lab Genetic Counselors: LabGC@seattlechildrens.org

Reference Range

Interpretive report will be provided

Methodology

Method: PCR + Sequencing

 

Limitations: This test is for targeted known mutation analysis only.  Mutations must be known.

CPT Codes

81403 (updated 1/20/16 by jconta)

Special Instructions

Please provide copies of proband reports when requesting known mutation analysis for cases NOT performed by Seattle Children's Lab.

 

Links to: Glycogen Storage Disease Type II (Pompe Disease) GeneReview

Requisition

Molecular Genetics

Clinical Utility

Pompe disease (glycogen storage disease type II) is an inherited disorder of glycogen metabolism, caused by mutations in the GAA gene and a deficiency of the enzyme alpha-glucosidase (also called acid-maltase). Pompe disease is a type of lysosomal storage disease. Individuals with Pompe disease are unable to use the glycogen stored in the lysosomes for energy, resulting in the progressive storage of glycogen in the heart, liver, and skeletal muscle. Pompe disease can present in infancy with profound hypotonia, cardiomegaly and cardiomyopathy or later in childhood and adulthood with progressive muscle weakness and respiratory insufficiency. Late onset Pompe disease presenting in the second to seventh decade of life can appear similar to a limb-girdle muscular dystrophy with lower limb proximal weakness.