There is a need for more research into Leigh syndrome, as there are currently no FDA-approved treatments, and the patient population faces an unmet need. However, in order for there to be progress towards therapies, there must be a thorough understanding of the disease itself.

Recently, researchers from the Mitochondrial Medicine Frontier Program at Children’s Hospital of Philadelphia (CHOP) have conducted a study to advance our understanding of Leigh disease. Specifically, they focused on developmental delays as predictors of patient outcomes.

About the Study

In our current understanding of Leigh syndrome, we view developmental delays and disabilities as later symptoms of the disease, appearing after neurologic regression and metabolic stroke. However, researchers noticed that there were rare instances in which this developmental delay preceded other symptoms.

To investigate this, the research team utilized and analyzed existing data from 69 Leigh syndrome patients. They wanted to see if earlier developmental delay was more common than they thought. Their findings include:

• 53 patients experienced neurodevelopmental regression
• 47 patients saw primary developmental delays before any neurologic regression
• Patients were grouped by three different phenotypes:
  • Primary developmental delay that happens before neurologic regression
    • 31 patients fell into this category
  • Primary developmental delay without neurologic regression occurring afterward
    • 16 patients fell into this category
  • Regression without any developmental delay following
    • 22 patients fell into this category
• Leigh syndrome patients with a history of primary developmental delay were found to experience worse outcomes

The knowledge that was gathered from this study could help to improve diagnosis of Leigh syndrome. Knowing that developmental delay may present earlier than previously thought may help more patients receive a diagnosis earlier.

About Leigh Syndrome

Leigh syndrome is a neurological condition that typically sees onset during infancy, although some do not experience symptoms until adulthood. Caused by an alteration in one of 75 possible genes, this syndrome is characterized by the deterioration of motor and mental abilities. Symptoms include:

• Failure to thrive
• Vomiting, diarrhea
• Trouble swallowing
• Weak muscle tone
• Ataxia
• Dystonia
• Rapid eye movements
• Lactate buildup
• Respiratory issues
• Rapid eye movements
• Paralysis of the muscles that move the eyes
• Hypertrophic cardiomyopathy
• Death of the nerves that transfer information from the eyes to the brain

The mutations that cause these symptoms can be inherited in a number of patterns, simply due to the sheer amount of possible genes. Inheritance in an autosomal recessive pattern or mitochondrial pattern is the most common. In terms of treatment, there is no cure. Doctors often utilize thiamine or thiamine derivatives, and they suggest a diet that is low in carbs and high in fat. Both methods are meant to slow disease progression.

Find the source article here.