Leigh syndrome
Leigh syndrome (also called Leigh disease and subacute necrotizing encephalomyelopathy) is an inherited neurometabolic disorder that affects the central nervous system. It is named after Archibald Denis Leigh, a British neuropsychiatrist who first described the condition in 1951. Normal levels of thiamine, thiamine monophosphate, and thiamine diphosphate are commonly found, but there is a reduced or absent level of thiamine triphosphate. This is thought to be caused by a blockage in the enzyme thiamine-diphosphate kinase, and therefore treatment in some patients would be to take thiamine triphosphate daily. Signs and symptoms The symptoms of Leigh syndrome were classically described as beginning in infancy and leading to death within a span of several years; however, as more cases are recognized, it is apparent that symptoms can emerge at any age—including adolescence or adulthood—and patients can survive for many years following diagnosis. Symptoms are often first seen after a triggering event that taxes the body's energy production, such as an infection or surgery. The general course of Leigh syndrome is one of episodic developmental regression during times of metabolic stress. Some patients have long periods without disease progression while others develop progressive decline. Infants with the syndrome have symptoms that include diarrhea,