Glycogen storage disease type Ib (GSDIb) is a disorder characterized by low blood glucose levels and an accumulation of fat and glycogen, leading to organ and tissue damage. It is caused by variants in the SLC37A4 gene that inhibit the function of the glucose-6-phosphatase translocase enzyme, preventing the normal metabolism of glucose-6-phosphate.
Take this test to find out if you are a genetic carrier for GSDIb and are at risk of passing a SLC37A4 variant to your children.
GSDIb is caused by variants in the SLC37A4 gene. This gene provides instructions for the glucose-6-phosphate translocase enzyme, which works in conjuction with glucose-6-phosphatase (encoded by the G6PC gene) to break down glucose-6-phosphate into the simple sugar glucose (the main energy source for many cells within the body).
Affected people produce a nonfunctional glucose-6-phosphate translocase enzyme, impairing the metabolism of glucose-6-phosphate. Instead glucose-6-phosphate is converted to fat and glycogen, which accumulates in organs and tissues, particularly the liver and kidneys.
GSD1b is an autosomal recessive disorder, meaning that a person must inherit two defective copies of the SLC37A4 gene for symptoms to occur.
This test detects two genetic variants of the SLC37A4 gene that account for approximately 42% of GSDIb carriers of Japanese descent, 39% of carriers of Serbian descent, and 31% of carriers of European descent.
Understanding your carrier status for these variants will help you understand the risk of passing a variant to your children.
- Low blood sugar
- Hepatomegaly (enlarged liver)
- Accumulation of lactic acid in the body (lactic acidosis)
- High uric acid levels (hyperuricemia)
- Excess fat in the blood (hyperlipidemia)
- Doll-like faces with fat cheeks
- Relatively thin arms and legs
- Short stature
- A protruding abdomen from enlarged liver and kidneys
- Impaired platelet function leading to bleeding
How It Works
Step 1: Sign up for a free DNA Access account.
Step 2: Upload your DNA markers to DNA Access.
Step 3: Log in to your account to access your results when they are ready.