Definition

Glycogen storage diseases (GSD) are hereditary metabolic disorders caused by defects in the enzymes responsible for glycogen synthesis/breakdown; comprehensive NGS panels screen genes such as AGL, G6PC, GAA, GBE1, GYS2, PHKA2, PYGL, PYGM, and SLC37A4. Hepatic forms present with hypoglycemia and hepatomegaly, while myopathic forms present with exercise intolerance and muscle pain.

Gene/region examined

PGAM2, PGM1, GAA, ENO3, G6PC1, PHKA2, LDHA, GBE1, AGL, PHKG2, PHKB, PYGM, PYGL, PHKA1, GYS2, PFKM, SLC37A4

Method

Next-Generation Sequencing, CNV Analysis

Accepted sample types

EDTA Blood

Description

17 gene regions associated with Glycogen Storage Diseases are analyzed.

Inheritance

Germline/hereditary, the metabolic disease genes screened are mostly autosomal recessive (some are X-linked).

Related Tests

Inheritance Patterns

Describes how a genetic condition is passed on within a family. There are five main patterns

Go to term →

Carrier (Heterozygous / Homozygous)

Why it matters: In autosomal recessive inheritance, when each parent is a carrier (while both appear healthy), the chance of their child being born with the disease is 25% in each

Go to term →

VUS (Variant of Uncertain Significance)

This is the situation where the test has detected a change in the DNA, but the role of this change in the development of disease is unconfirmed.

Go to term →

How to Read a Genetic Test Result (Positive / Negative / VUS)

A genetic test result falls into three main categories

Go to term →

Types of Genetic Tests

A genetic test is a type of medical test that detects changes in genes, chromosomes or proteins. Today there are more than 77,000 genetic tests available.

Go to term →