GLUT1 Deficiency Syndrome in Adulthood

Hello and welcome to Science with Sandra!

In this edition, I would like to share a summary of a recent publication by an Italian research group of  Dr. Pierangelo Veggiotti and collaborators in Milan, Italy, titled: “GLUT1 Deficiency Syndrome in Adulthood: Lost in Diagnosis.”

The goal of this study was to describe the symptoms experienced by adults with GLUT1 Deficiency and to assess their impact on emotional well-being, social life, and daily functioning. Additionally, the authors aimed to raise awareness, especially among adult neurologists, by highlighting milder adult cases and the consequences of delayed diagnosis and lack of appropriate care on independence and quality of life.

This study evaluated 32 adults in Italy with genetically confirmed GLUT1 Deficiency to better understand what life is like for adults with this condition, how long it takes to receive a diagnosis, and what types of care adults may need.

GLUT1 Deficiency is often thought of as a childhood condition. However, many individuals reach adulthood without a diagnosis or are diagnosed only after their child, or another family member receives one. Little research has focused on adults with GLUT1 Deficiency, including their symptoms, emotional health, daily challenges, and overall quality of life. This publication provides important insights into the adult experience, particularly in cases of late diagnosis.

What Were the Study Findings?

1. Delayed diagnosis

Symptoms typically began in early childhood, around 2 years of age. However, the average age at diagnosis was 26 years, meaning that many adults waited nearly 18 years to receive an accurate diagnosis.

• 69% of participants were diagnosed due to typical GLUT1 Deficiency symptoms, and over half of these individuals were already adults.
• About 30% were diagnosed only after a family member received a diagnosis.
• Two participants were asymptomatic.

2. Symptoms are often mild and variable

Most adults experienced symptoms typical of GLUT1 Deficiency. Common symptoms included:

• Seizures
• Movement disorders, especially paroxysmal movement disorders
• Psychomotor delay
• Paroxysmal eye-head movements
• Febrile seizures and hemiplegic migraine
• Intellectual disability

3. Movement problems often replace seizures in adulthood

While seizures tend to improve with age, movement disorders become the main challenge for many adults.

These episodes are often triggered by:

• Stress
• Fatigue
• Fever
• Hormonal changes

These findings highlight the importance of tracking symptoms and identifying personal triggers, which may help prevent or reduce episodes when possible.

Additionally, about 16% of participants reported sleep disturbances, including difficulty falling asleep, poor sleep quality, frequent awakenings, and daytime sleepiness. The combination of fatigue and sleep problems underscores the importance of adequate rest, which may impact work, school, and social activities.

4. Emotional and mental health challenges are common

Many adults experienced emotional and mental health challenges, including:

• Anxiety (42%)
• Depression or low mood (58%)
• Irritability (37%)
• Euphoria (26%)
• Aggression, appetite disturbances, and disinhibition (5%)

These findings indicate significant emotional vulnerability. Many participants reported feeling different, misunderstood, or like a burden to others, which often led to feelings of loneliness.

5. Daily life, independence, and work are impacted

Some adults required assistance with daily tasks. Approximately 35% were unemployed, often due to fatigue, movement episodes, speech difficulties, and challenges with social interactions.

Many participants completed high school, and some obtained university degrees. Others completed vocational training or primary or middle school only, highlighting the wide variability in intellectual and functional outcomes within our population.

6. Ketogenic diet helps but is hard to maintain in adulthood

The ketogenic diet improved symptoms for many participants. However, around half discontinued the diet, primarily because it was perceived as highly restrictive and difficult to maintain alongside social and professional activities.

This highlights the need for more flexible and sustainable treatment options for adults, allowing greater independence and quality of life.

7. Adults need multidisciplinary care

The authors emphasize that adults with GLUT1 Deficiency benefit most from a multidisciplinary care approach, involving:

• Neurologists
• Dietitians
• Physical, occupational, and speech therapists
• Psychologists
• Social support services

This team-based approach supports physical health, mental well-being, independence, and overall quality of life.

Final Thoughts

In summary, this study raises awareness of milder adult presentations of GLUT1 Deficiency that are frequently missed, leading to delayed diagnosis and insufficient clinical care. The lack of appropriate support can significantly hinder independence, educational achievement, and work performance.

We sincerely thank Dr. Veggiotti and his collaborators for their valuable contribution and for shedding light on the lived experiences of adults in the GLUT1 Deficiency community.

Thank you for visiting our blog. If you have any questions, please feel free to contact me at [email protected].