Glucose-6-phosphate translocase deficiency

Glucose-6-phosphate translocase deficiency is a rare genetic disorder that affects the body's ability to regulate blood sugar levels. This condition is part of a group of diseases known as Glycogen Storage Diseases (GSDs), specifically classified as type 1b. It is caused by mutations in the SLC37A4 gene, which encodes the glucose-6-phosphate translocase enzyme. This enzyme is crucial for the proper functioning of the gluconeogenesis and glycogenolysis pathways, which are responsible for maintaining stable blood glucose levels.

Symptoms and Diagnosis

Individuals with glucose-6-phosphate translocase deficiency typically present symptoms in infancy or early childhood. The hallmark symptoms include hypoglycemia (low blood sugar levels), growth retardation, and a distended abdomen due to an enlarged liver (hepatomegaly). Other symptoms may include neutropenia (a reduction in the number of white blood cells), which increases susceptibility to infections, and a condition known as inflammatory bowel disease (IBD).

Diagnosis of glucose-6-phosphate translocase deficiency is based on clinical presentation, biochemical tests showing abnormal blood sugar and lactate levels, and genetic testing confirming mutations in the SLC37A4 gene.

Treatment

Management of glucose-6-phosphate translocase deficiency involves maintaining normal blood glucose levels through dietary interventions. This includes frequent, carbohydrate-rich meals and the administration of uncooked cornstarch, which provides a slow-release form of glucose. In cases of neutropenia, antibiotics may be prescribed to prevent or treat infections. Growth hormone therapy may be considered for patients experiencing significant growth retardation.

Genetics

The SLC37A4 gene mutations responsible for glucose-6-phosphate translocase deficiency are inherited in an autosomal recessive pattern. This means that an individual must inherit two copies of the mutated gene, one from each parent, to be affected by the disorder. Carriers, who have only one copy of the mutation, typically do not show symptoms of the disease.

See Also

• Glycogen storage disease type I
• Hypoglycemia
• Gluconeogenesis
• Glycogenolysis