E74.810 Glucose transporter protein type 1 deficiency

Name of the Condition

• Glucose transporter protein type 1 deficiency (ICD-10 Code E74.810)

Summary

Glucose transporter protein type 1 deficiency is a rare genetic disorder that impairs the transport of glucose across the blood-brain barrier. This disruption leads to reduced glucose availability in the central nervous system, resulting in neurological symptoms. The condition is characterized by developmental delays, seizures, and other neurologic manifestations due to insufficient energy supply to the brain.

Causes

The condition is caused by mutations in the SLC2A1 gene, which encodes the glucose transporter protein type 1 (GLUT1). These mutations disrupt the function of the transporter, preventing adequate glucose from crossing the blood-brain barrier. The disorder is typically inherited in an autosomal dominant pattern, though de novo mutations can occur.

Risk Factors

• Genetic predisposition, such as a family history of the disorder.
• Presence of SLC2A1 gene mutations.
• Inherited autosomal dominant transmission from an affected parent.

Symptoms

Symptoms typically appear in infancy or early childhood and may include:

• Developmental delays or intellectual disability.
• Recurrent seizures, often beginning in the first year of life.
• Movement disorders, such as ataxia or dystonia.
• Speech and language difficulties.
• Headaches or episodes of confusion.

Diagnosis

Diagnosis involves a combination of clinical evaluation, genetic testing, and laboratory studies. Cerebrospinal fluid (CSF) analysis may show low glucose levels relative to blood glucose. Genetic testing for SLC2A1 mutations confirms the diagnosis. Additional tests, such as EEG or MRI, may assess neurological involvement.

Treatment Options

Treatment focuses on managing symptoms and improving glucose delivery to the brain. A ketogenic diet, which provides an alternative energy source, is often effective. Antiepileptic medications control seizures. Physical and occupational therapy supports developmental progress. Regular monitoring by a neurologist is recommended.

Prognosis and Follow-Up

Prognosis varies depending on the severity of symptoms and response to treatment. Early diagnosis and intervention, particularly with a ketogenic diet, can improve outcomes. Long-term follow-up with a multidisciplinary team, including neurologists and dietitians, is essential to manage symptoms and adjust treatment as needed.

Complications

Potential complications include persistent seizures, developmental regression, and challenges with motor or cognitive function. Delayed treatment may worsen neurological outcomes. Some individuals may experience side effects from medications or dietary restrictions.

Lifestyle & Prevention

While the disorder is genetic and not preventable, managing symptoms through a ketogenic diet and regular medical care can improve quality of life. Families may benefit from genetic counseling to understand inheritance risks and plan for future pregnancies.

When to Seek Professional Help

Seek medical attention if symptoms such as seizures, developmental delays, or unexplained neurological issues appear in infancy or childhood. Early evaluation by a neurologist is critical for timely diagnosis and treatment initiation.

Tips for Medical Coders

When coding for glucose transporter protein type 1 deficiency, use ICD-10-CM code E74.810. Ensure documentation supports the diagnosis, including clinical findings, genetic testing results, and treatment plans. Verify that the code is not used for other glucose transport disorders. Accurate coding requires specificity in clinical notes to reflect the condition accurately.