CONDITION REFERENCE
Glycogen storage disease type VI
Information from MedlinePlus Genetics about this condition and how it can be inherited.
About this condition
Glycogen storage disease type VI (also known as GSDVI or Hers disease) is an inherited disorder caused by an inability to break down a complex sugar called glycogen in liver cells. A lack of glycogen breakdown interferes with the normal function of the liver.
The signs and symptoms of GSDVI typically begin in infancy to early childhood. The first sign is usually an enlarged liver (hepatomegaly). During prolonged periods without food (fasting), affected individuals may have low blood sugar (hypoglycemia) or elevated levels of ketones in the blood (ketosis). Ketones are molecules produced during the breakdown of fats, which occurs when stored sugars are unavailable. Children with GSDVI tend to grow slower than their peers, but they often achieve normal height as adults. Some affected children also have mild delays in the development of motor skills, such as sitting, standing, or walking.
The signs and symptoms of GSDVI tend to improve with age; most adults with this condition do not have any related health problems.
Inheritance
- Autosomal recessive
A condition can have several forms with different inheritance patterns. Each pattern may apply to a different gene or form of the condition.
Related genes
MedlinePlus lists these genes for this condition. Open a gene page to read any available ClinGen reviews and ClinVar records.
YOUR DNA FILE
What can your DNA file tell you?
Your DNA file only includes the positions your test checked and reported. Consumer DNA kits usually test selected positions. Sequencing files can also leave out positions that were not reported or where the test could not give a result.
A variant missing from your file does not mean you tested negative for it. A ClinVar classification applies to a particular variant and the condition or finding it was reported for. It does not apply to everyone with that gene. An uncertain finding cannot establish a diagnosis.
BioDecode reads supported DNA files on your computer. It cannot fill gaps in your test, diagnose a condition or replace clinical testing.
Sources and dates
The source information on this page last changed on 2026-09-18.
MedlinePlus Source details
Source release: Fri, 18 Sep 2026 05:17:13 GMT
Source publication: 2020-08-18
Source review: 2010-09
SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a
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